/*
 * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
 * Copyright (C) 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "platform/graphics/BitmapImage.h"

#include "platform/PlatformInstrumentation.h"
#include "platform/RuntimeEnabledFeatures.h"
#include "platform/Timer.h"
#include "platform/geometry/FloatRect.h"
#include "platform/graphics/BitmapImageMetrics.h"
#include "platform/graphics/DeferredImageDecoder.h"
#include "platform/graphics/ImageObserver.h"
#include "platform/graphics/StaticBitmapImage.h"
#include "platform/graphics/skia/SkiaUtils.h"
#include "platform/instrumentation/tracing/TraceEvent.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "wtf/PassRefPtr.h"
#include "wtf/PtrUtil.h"
#include "wtf/text/WTFString.h"

namespace blink {

namespace {

ColorBehavior defaultColorBehavior() {
  // TODO(ccameron): ColorBehavior should be specified by the caller requesting
  // SkImages.
  // https://crbug.com/667420
  if (RuntimeEnabledFeatures::trueColorRenderingEnabled())
    return ColorBehavior::tag();
  return ColorBehavior::transformToGlobalTarget();
}

}  // namespace

PassRefPtr<BitmapImage> BitmapImage::createWithOrientationForTesting(
    const SkBitmap& bitmap,
    ImageOrientation orientation) {
  if (bitmap.isNull()) {
    return BitmapImage::create();
  }

  RefPtr<BitmapImage> result = adoptRef(new BitmapImage(bitmap));
  result->m_frames[0].m_orientation = orientation;
  if (orientation.usesWidthAsHeight())
    result->m_sizeRespectingOrientation = result->m_size.transposedSize();
  return result.release();
}

BitmapImage::BitmapImage(ImageObserver* observer)
    : Image(observer),
      m_currentFrame(0),
      m_cachedFrameIndex(0),
      m_cachedFrameColorBehavior(defaultColorBehavior()),
      m_repetitionCount(cAnimationNone),
      m_repetitionCountStatus(Unknown),
      m_repetitionsComplete(0),
      m_desiredFrameStartTime(0),
      m_frameCount(0),
      m_animationPolicy(ImageAnimationPolicyAllowed),
      m_animationFinished(false),
      m_allDataReceived(false),
      m_haveSize(false),
      m_sizeAvailable(false),
      m_haveFrameCount(false) {}

BitmapImage::BitmapImage(const SkBitmap& bitmap, ImageObserver* observer)
    : Image(observer),
      m_size(bitmap.width(), bitmap.height()),
      m_currentFrame(0),
      m_cachedFrame(SkImage::MakeFromBitmap(bitmap)),
      m_cachedFrameIndex(0),
      m_cachedFrameColorBehavior(defaultColorBehavior()),
      m_repetitionCount(cAnimationNone),
      m_repetitionCountStatus(Unknown),
      m_repetitionsComplete(0),
      m_frameCount(1),
      m_animationPolicy(ImageAnimationPolicyAllowed),
      m_animationFinished(true),
      m_allDataReceived(true),
      m_haveSize(true),
      m_sizeAvailable(true),
      m_haveFrameCount(true) {
  // Since we don't have a decoder, we can't figure out the image orientation.
  // Set m_sizeRespectingOrientation to be the same as m_size so it's not 0x0.
  m_sizeRespectingOrientation = m_size;

  m_frames.grow(1);
  m_frames[0].m_hasAlpha = !bitmap.isOpaque();
  m_frames[0].m_haveMetadata = true;
}

BitmapImage::~BitmapImage() {
  stopAnimation();
}

bool BitmapImage::currentFrameHasSingleSecurityOrigin() const {
  return true;
}

void BitmapImage::destroyDecodedData() {
  m_cachedFrame.reset();
  for (size_t i = 0; i < m_frames.size(); ++i)
    m_frames[i].clear(true);
  m_source.clearCacheExceptFrame(kNotFound);
  notifyMemoryChanged();
}

PassRefPtr<SharedBuffer> BitmapImage::data() {
  return m_source.data();
}

void BitmapImage::notifyMemoryChanged() {
  if (getImageObserver())
    getImageObserver()->decodedSizeChangedTo(this, totalFrameBytes());
}

size_t BitmapImage::totalFrameBytes() {
  const size_t numFrames = frameCount();
  size_t totalBytes = 0;
  for (size_t i = 0; i < numFrames; ++i)
    totalBytes += m_source.frameBytesAtIndex(i);
  return totalBytes;
}

sk_sp<SkImage> BitmapImage::decodeAndCacheFrame(
    size_t index,
    const ColorBehavior& colorBehavior) {
  size_t numFrames = frameCount();
  if (m_frames.size() < numFrames)
    m_frames.grow(numFrames);

  // We are caching frame snapshots.  This is OK even for partially decoded
  // frames, as they are cleared by dataChanged() when new data arrives.
  sk_sp<SkImage> image = m_source.createFrameAtIndex(index, colorBehavior);
  m_cachedFrame = image;
  m_cachedFrameIndex = index;
  m_cachedFrameColorBehavior = colorBehavior;

  m_frames[index].m_orientation = m_source.orientationAtIndex(index);
  m_frames[index].m_haveMetadata = true;
  m_frames[index].m_isComplete = m_source.frameIsCompleteAtIndex(index);
  if (repetitionCount(false) != cAnimationNone)
    m_frames[index].m_duration = m_source.frameDurationAtIndex(index);
  m_frames[index].m_hasAlpha = m_source.frameHasAlphaAtIndex(index);
  m_frames[index].m_frameBytes = m_source.frameBytesAtIndex(index);

  notifyMemoryChanged();
  return image;
}

void BitmapImage::updateSize() const {
  if (!m_sizeAvailable || m_haveSize)
    return;

  m_size = m_source.size();
  m_sizeRespectingOrientation = m_source.size(RespectImageOrientation);
  m_haveSize = true;
}

IntSize BitmapImage::size() const {
  updateSize();
  return m_size;
}

IntSize BitmapImage::sizeRespectingOrientation() const {
  updateSize();
  return m_sizeRespectingOrientation;
}

bool BitmapImage::getHotSpot(IntPoint& hotSpot) const {
  return m_source.getHotSpot(hotSpot);
}

Image::SizeAvailability BitmapImage::setData(PassRefPtr<SharedBuffer> data,
                                             bool allDataReceived) {
  if (!data.get())
    return SizeAvailable;

  int length = data->size();
  if (!length)
    return SizeAvailable;

  // If ImageSource::setData() fails, we know that this is a decode error.
  // Report size available so that it gets registered as such in
  // ImageResourceContent.
  if (!m_source.setData(std::move(data), allDataReceived))
    return SizeAvailable;

  return dataChanged(allDataReceived);
}

Image::SizeAvailability BitmapImage::dataChanged(bool allDataReceived) {
  TRACE_EVENT0("blink", "BitmapImage::dataChanged");

  // Clear all partially-decoded frames. For most image formats, there is only
  // one frame, but at least GIF and ICO can have more. With GIFs, the frames
  // come in order and we ask to decode them in order, waiting to request a
  // subsequent frame until the prior one is complete. Given that we clear
  // incomplete frames here, this means there is at most one incomplete frame
  // (even if we use destroyDecodedData() -- since it doesn't reset the
  // metadata), and it is after all the complete frames.
  //
  // With ICOs, on the other hand, we may ask for arbitrary frames at
  // different times (e.g. because we're displaying a higher-resolution image
  // in the content area and using a lower-resolution one for the favicon),
  // and the frames aren't even guaranteed to appear in the file in the same
  // order as in the directory, so an arbitrary number of the frames might be
  // incomplete (if we ask for frames for which we've not yet reached the
  // start of the frame data), and any or none of them might be the particular
  // frame affected by appending new data here. Thus we have to clear all the
  // incomplete frames to be safe.
  for (size_t i = 0; i < m_frames.size(); ++i) {
    // NOTE: Don't call frameIsCompleteAtIndex() here, that will try to
    // decode any uncached (i.e. never-decoded or
    // cleared-on-a-previous-pass) frames!
    if (m_frames[i].m_haveMetadata && !m_frames[i].m_isComplete) {
      m_frames[i].clear(true);
      if (i == m_cachedFrameIndex)
        m_cachedFrame.reset();
    }
  }

  // Feed all the data we've seen so far to the image decoder.
  m_allDataReceived = allDataReceived;

  m_haveFrameCount = false;
  return isSizeAvailable() ? SizeAvailable : SizeUnavailable;
}

bool BitmapImage::hasColorProfile() const {
  return m_source.hasColorProfile();
}

String BitmapImage::filenameExtension() const {
  return m_source.filenameExtension();
}

void BitmapImage::draw(
    SkCanvas* canvas,
    const SkPaint& paint,
    const FloatRect& dstRect,
    const FloatRect& srcRect,
    RespectImageOrientationEnum shouldRespectImageOrientation,
    ImageClampingMode clampMode,
    const ColorBehavior& colorBehavior) {
  TRACE_EVENT0("skia", "BitmapImage::draw");

  sk_sp<SkImage> image = imageForCurrentFrame(colorBehavior);
  if (!image)
    return;  // It's too early and we don't have an image yet.

  FloatRect adjustedSrcRect = srcRect;
  adjustedSrcRect.intersect(SkRect::Make(image->bounds()));

  if (adjustedSrcRect.isEmpty() || dstRect.isEmpty())
    return;  // Nothing to draw.

  ImageOrientation orientation = DefaultImageOrientation;
  if (shouldRespectImageOrientation == RespectImageOrientation)
    orientation = frameOrientationAtIndex(m_currentFrame);

  SkAutoCanvasRestore autoRestore(canvas, false);
  FloatRect adjustedDstRect = dstRect;
  if (orientation != DefaultImageOrientation) {
    canvas->save();

    // ImageOrientation expects the origin to be at (0, 0)
    canvas->translate(adjustedDstRect.x(), adjustedDstRect.y());
    adjustedDstRect.setLocation(FloatPoint());

    canvas->concat(affineTransformToSkMatrix(
        orientation.transformFromDefault(adjustedDstRect.size())));

    if (orientation.usesWidthAsHeight()) {
      // The destination rect will have its width and height already reversed
      // for the orientation of the image, as it was needed for page layout, so
      // we need to reverse it back here.
      adjustedDstRect =
          FloatRect(adjustedDstRect.x(), adjustedDstRect.y(),
                    adjustedDstRect.height(), adjustedDstRect.width());
    }
  }

  canvas->drawImageRect(image.get(), adjustedSrcRect, adjustedDstRect, &paint,
                        WebCoreClampingModeToSkiaRectConstraint(clampMode));

  if (image->isLazyGenerated())
    PlatformInstrumentation::didDrawLazyPixelRef(image->uniqueID());

  startAnimation();
}

size_t BitmapImage::frameCount() {
  if (!m_haveFrameCount) {
    m_frameCount = m_source.frameCount();
    // If decoder is not initialized yet, m_source.frameCount() returns 0.
    if (m_frameCount)
      m_haveFrameCount = true;
  }

  return m_frameCount;
}

static inline bool hasVisibleImageSize(IntSize size) {
  return (size.width() > 1 || size.height() > 1);
}

bool BitmapImage::isSizeAvailable() {
  if (m_sizeAvailable)
    return true;

  m_sizeAvailable = m_source.isSizeAvailable();

  if (m_sizeAvailable && hasVisibleImageSize(size())) {
    BitmapImageMetrics::countDecodedImageType(m_source.filenameExtension());
    if (m_source.filenameExtension() == "jpg")
      BitmapImageMetrics::countImageOrientation(
          m_source.orientationAtIndex(0).orientation());
  }

  return m_sizeAvailable;
}

sk_sp<SkImage> BitmapImage::frameAtIndex(size_t index,
                                         const ColorBehavior& colorBehavior) {
  if (index >= frameCount())
    return nullptr;

  if (index == m_cachedFrameIndex && m_cachedFrame &&
      m_cachedFrameColorBehavior == colorBehavior)
    return m_cachedFrame;

  return decodeAndCacheFrame(index, colorBehavior);
}

bool BitmapImage::frameIsCompleteAtIndex(size_t index) const {
  if (index < m_frames.size() && m_frames[index].m_haveMetadata &&
      m_frames[index].m_isComplete)
    return true;

  return m_source.frameIsCompleteAtIndex(index);
}

float BitmapImage::frameDurationAtIndex(size_t index) const {
  if (index < m_frames.size() && m_frames[index].m_haveMetadata)
    return m_frames[index].m_duration;

  return m_source.frameDurationAtIndex(index);
}

sk_sp<SkImage> BitmapImage::imageForCurrentFrame(
    const ColorBehavior& colorBehavior) {
  return frameAtIndex(currentFrame(), colorBehavior);
}

PassRefPtr<Image> BitmapImage::imageForDefaultFrame() {
  // TODO(ccameron): Determine the appropriate ColorBehavior for this situation.
  // https://crbug.com/667420
  const ColorBehavior& colorBehavior = m_cachedFrameColorBehavior;
  if (frameCount() > 1) {
    sk_sp<SkImage> firstFrame = frameAtIndex(0, colorBehavior);
    if (firstFrame)
      return StaticBitmapImage::create(std::move(firstFrame));
  }

  return Image::imageForDefaultFrame();
}

bool BitmapImage::frameHasAlphaAtIndex(size_t index) {
  if (m_frames.size() <= index)
    return true;

  if (m_frames[index].m_haveMetadata && !m_frames[index].m_hasAlpha)
    return false;

  // m_hasAlpha may change after m_haveMetadata is set to true, so always ask
  // ImageSource for the value if the cached value is the default value.
  bool hasAlpha = m_source.frameHasAlphaAtIndex(index);

  if (m_frames[index].m_haveMetadata)
    m_frames[index].m_hasAlpha = hasAlpha;

  return hasAlpha;
}

bool BitmapImage::currentFrameKnownToBeOpaque(MetadataMode metadataMode) {
  if (metadataMode == PreCacheMetadata) {
    // frameHasAlphaAtIndex() conservatively returns false for uncached frames.
    // To increase the chance of an accurate answer, pre-cache the current frame
    // metadata. Because ColorBehavior does not affect this result, use
    // whatever ColorBehavior was last used (if any).
    frameAtIndex(currentFrame(), m_cachedFrameColorBehavior);
  }
  return !frameHasAlphaAtIndex(currentFrame());
}

bool BitmapImage::currentFrameIsComplete() {
  return frameIsCompleteAtIndex(currentFrame());
}

bool BitmapImage::currentFrameIsLazyDecoded() {
  // Because ColorBehavior does not affect this result, use whatever
  // ColorBehavior was last used (if any).
  sk_sp<SkImage> image =
      frameAtIndex(currentFrame(), m_cachedFrameColorBehavior);
  return image && image->isLazyGenerated();
}

ImageOrientation BitmapImage::currentFrameOrientation() {
  return frameOrientationAtIndex(currentFrame());
}

ImageOrientation BitmapImage::frameOrientationAtIndex(size_t index) {
  if (m_frames.size() <= index)
    return DefaultImageOrientation;

  if (m_frames[index].m_haveMetadata)
    return m_frames[index].m_orientation;

  return m_source.orientationAtIndex(index);
}

int BitmapImage::repetitionCount(bool imageKnownToBeComplete) {
  if ((m_repetitionCountStatus == Unknown) ||
      ((m_repetitionCountStatus == Uncertain) && imageKnownToBeComplete)) {
    // Snag the repetition count.  If |imageKnownToBeComplete| is false, the
    // repetition count may not be accurate yet for GIFs; in this case the
    // decoder will default to cAnimationLoopOnce, and we'll try and read
    // the count again once the whole image is decoded.
    m_repetitionCount = m_source.repetitionCount();
    m_repetitionCountStatus =
        (imageKnownToBeComplete || m_repetitionCount == cAnimationNone)
            ? Certain
            : Uncertain;
  }
  return m_repetitionCount;
}

bool BitmapImage::shouldAnimate() {
  bool animated = repetitionCount(false) != cAnimationNone &&
                  !m_animationFinished && getImageObserver();
  if (animated && m_animationPolicy == ImageAnimationPolicyNoAnimation)
    animated = false;
  return animated;
}

void BitmapImage::startAnimation(CatchUpAnimation catchUpIfNecessary) {
  if (m_frameTimer || !shouldAnimate() || frameCount() <= 1)
    return;

  // If we aren't already animating, set now as the animation start time.
  const double time = monotonicallyIncreasingTime();
  if (!m_desiredFrameStartTime)
    m_desiredFrameStartTime = time;

  // Don't advance the animation to an incomplete frame.
  size_t nextFrame = (m_currentFrame + 1) % frameCount();
  if (!m_allDataReceived && !frameIsCompleteAtIndex(nextFrame))
    return;

  // Don't advance past the last frame if we haven't decoded the whole image
  // yet and our repetition count is potentially unset.  The repetition count
  // in a GIF can potentially come after all the rest of the image data, so
  // wait on it.
  if (!m_allDataReceived &&
      (repetitionCount(false) == cAnimationLoopOnce ||
       m_animationPolicy == ImageAnimationPolicyAnimateOnce) &&
      m_currentFrame >= (frameCount() - 1))
    return;

  // Determine time for next frame to start.  By ignoring paint and timer lag
  // in this calculation, we make the animation appear to run at its desired
  // rate regardless of how fast it's being repainted.
  const double currentDuration = frameDurationAtIndex(m_currentFrame);
  m_desiredFrameStartTime += currentDuration;

  // When an animated image is more than five minutes out of date, the
  // user probably doesn't care about resyncing and we could burn a lot of
  // time looping through frames below.  Just reset the timings.
  const double cAnimationResyncCutoff = 5 * 60;
  if ((time - m_desiredFrameStartTime) > cAnimationResyncCutoff)
    m_desiredFrameStartTime = time + currentDuration;

  // The image may load more slowly than it's supposed to animate, so that by
  // the time we reach the end of the first repetition, we're well behind.
  // Clamp the desired frame start time in this case, so that we don't skip
  // frames (or whole iterations) trying to "catch up".  This is a tradeoff:
  // It guarantees users see the whole animation the second time through and
  // don't miss any repetitions, and is closer to what other browsers do; on
  // the other hand, it makes animations "less accurate" for pages that try to
  // sync an image and some other resource (e.g. audio), especially if users
  // switch tabs (and thus stop drawing the animation, which will pause it)
  // during that initial loop, then switch back later.
  if (nextFrame == 0 && m_repetitionsComplete == 0 &&
      m_desiredFrameStartTime < time)
    m_desiredFrameStartTime = time;

  if (catchUpIfNecessary == DoNotCatchUp || time < m_desiredFrameStartTime) {
    // Haven't yet reached time for next frame to start; delay until then.
    m_frameTimer = WTF::wrapUnique(
        new Timer<BitmapImage>(this, &BitmapImage::advanceAnimation));
    m_frameTimer->startOneShot(std::max(m_desiredFrameStartTime - time, 0.),
                               BLINK_FROM_HERE);
  } else {
    // We've already reached or passed the time for the next frame to start.
    // See if we've also passed the time for frames after that to start, in
    // case we need to skip some frames entirely.  Remember not to advance
    // to an incomplete frame.
    for (size_t frameAfterNext = (nextFrame + 1) % frameCount();
         frameIsCompleteAtIndex(frameAfterNext);
         frameAfterNext = (nextFrame + 1) % frameCount()) {
      // Should we skip the next frame?
      double frameAfterNextStartTime =
          m_desiredFrameStartTime + frameDurationAtIndex(nextFrame);
      if (time < frameAfterNextStartTime)
        break;

      // Skip the next frame by advancing the animation forward one frame.
      if (!internalAdvanceAnimation(SkipFramesToCatchUp)) {
        DCHECK(m_animationFinished);
        return;
      }
      m_desiredFrameStartTime = frameAfterNextStartTime;
      nextFrame = frameAfterNext;
    }

    // Post a task to advance the frame immediately. m_desiredFrameStartTime
    // may be in the past, meaning the next time through this function we'll
    // kick off the next advancement sooner than this frame's duration would
    // suggest.
    m_frameTimer = WTF::wrapUnique(new Timer<BitmapImage>(
        this, &BitmapImage::advanceAnimationWithoutCatchUp));
    m_frameTimer->startOneShot(0, BLINK_FROM_HERE);
  }
}

void BitmapImage::stopAnimation() {
  // This timer is used to animate all occurrences of this image.  Don't
  // invalidate the timer unless all renderers have stopped drawing.
  m_frameTimer.reset();
}

void BitmapImage::resetAnimation() {
  stopAnimation();
  m_currentFrame = 0;
  m_repetitionsComplete = 0;
  m_desiredFrameStartTime = 0;
  m_animationFinished = false;
  m_cachedFrame.reset();
}

bool BitmapImage::maybeAnimated() {
  if (m_animationFinished)
    return false;
  if (frameCount() > 1)
    return true;

  return m_source.repetitionCount() != cAnimationNone;
}

void BitmapImage::advanceTime(double deltaTimeInSeconds) {
  if (m_desiredFrameStartTime)
    m_desiredFrameStartTime -= deltaTimeInSeconds;
  else
    m_desiredFrameStartTime =
        monotonicallyIncreasingTime() - deltaTimeInSeconds;
}

void BitmapImage::advanceAnimation(TimerBase*) {
  internalAdvanceAnimation();
  // At this point the image region has been marked dirty, and if it's
  // onscreen, we'll soon make a call to draw(), which will call
  // startAnimation() again to keep the animation moving.
}

void BitmapImage::advanceAnimationWithoutCatchUp(TimerBase*) {
  if (internalAdvanceAnimation())
    startAnimation(DoNotCatchUp);
}

bool BitmapImage::internalAdvanceAnimation(AnimationAdvancement advancement) {
  // Stop the animation.
  stopAnimation();

  // See if anyone is still paying attention to this animation.  If not, we
  // don't advance, and will remain suspended at the current frame until the
  // animation is resumed.
  if (advancement != SkipFramesToCatchUp &&
      getImageObserver()->shouldPauseAnimation(this))
    return false;

  if (m_currentFrame + 1 < frameCount()) {
    m_currentFrame++;
  } else {
    m_repetitionsComplete++;

    // Get the repetition count again. If we weren't able to get a
    // repetition count before, we should have decoded the whole image by
    // now, so it should now be available.
    // We don't need to special-case cAnimationLoopOnce here because it is
    // 0 (see comments on its declaration in ImageAnimation.h).
    if ((repetitionCount(true) != cAnimationLoopInfinite &&
         m_repetitionsComplete > m_repetitionCount) ||
        m_animationPolicy == ImageAnimationPolicyAnimateOnce) {
      m_animationFinished = true;
      m_desiredFrameStartTime = 0;

      // We skipped to the last frame and cannot advance further. The
      // observer will not receive animationAdvanced notifications while
      // skipping but we still need to notify the observer to draw the
      // last frame. Skipping frames occurs while painting so we do not
      // synchronously notify the observer which could cause a layout.
      if (advancement == SkipFramesToCatchUp) {
        m_frameTimer = WTF::wrapUnique(new Timer<BitmapImage>(
            this, &BitmapImage::notifyObserversOfAnimationAdvance));
        m_frameTimer->startOneShot(0, BLINK_FROM_HERE);
      }

      return false;
    }

    // Loop the animation back to the first frame.
    m_currentFrame = 0;
  }

  // We need to draw this frame if we advanced to it while not skipping.
  if (advancement != SkipFramesToCatchUp)
    getImageObserver()->animationAdvanced(this);

  return true;
}

void BitmapImage::notifyObserversOfAnimationAdvance(TimerBase*) {
  getImageObserver()->animationAdvanced(this);
}

}  // namespace blink