diff --git a/gfx/angle/src/libEGL/Surface.cpp b/gfx/angle/src/libEGL/Surface.cpp
--- a/gfx/angle/src/libEGL/Surface.cpp
+++ b/gfx/angle/src/libEGL/Surface.cpp
@@ -285,17 +285,17 @@ void Surface::subclassWindow()
     DWORD processId;
     DWORD threadId = GetWindowThreadProcessId(mWindow, &processId);
     if (processId != GetCurrentProcessId() || threadId != GetCurrentThreadId())
     {
         return;
     }
 
     SetLastError(0);
-    LONG oldWndProc = SetWindowLong(mWindow, GWL_WNDPROC, reinterpret_cast<LONG>(SurfaceWindowProc));
+    LONG_PTR oldWndProc = SetWindowLongPtr(mWindow, GWLP_WNDPROC, reinterpret_cast<LONG_PTR>(SurfaceWindowProc));
     if(oldWndProc == 0 && GetLastError() != ERROR_SUCCESS)
     {
         mWindowSubclassed = false;
         return;
     }
 
     SetProp(mWindow, kSurfaceProperty, reinterpret_cast<HANDLE>(this));
     SetProp(mWindow, kParentWndProc, reinterpret_cast<HANDLE>(oldWndProc));
@@ -305,27 +305,27 @@ void Surface::subclassWindow()
 void Surface::unsubclassWindow()
 {
     if(!mWindowSubclassed)
     {
         return;
     }
 
     // un-subclass
-    LONG parentWndFunc = reinterpret_cast<LONG>(GetProp(mWindow, kParentWndProc));
+    LONG_PTR parentWndFunc = reinterpret_cast<LONG_PTR>(GetProp(mWindow, kParentWndProc));
 
     // Check the windowproc is still SurfaceWindowProc.
     // If this assert fails, then it is likely the application has subclassed the
     // hwnd as well and did not unsubclass before destroying its EGL context. The
     // application should be modified to either subclass before initializing the
     // EGL context, or to unsubclass before destroying the EGL context.
     if(parentWndFunc)
     {
-        LONG prevWndFunc = SetWindowLong(mWindow, GWL_WNDPROC, parentWndFunc);
-        ASSERT(prevWndFunc == reinterpret_cast<LONG>(SurfaceWindowProc));
+        LONG_PTR prevWndFunc = SetWindowLongPtr(mWindow, GWLP_WNDPROC, parentWndFunc);
+        ASSERT(prevWndFunc == reinterpret_cast<LONG_PTR>(SurfaceWindowProc));
     }
 
     RemoveProp(mWindow, kSurfaceProperty);
     RemoveProp(mWindow, kParentWndProc);
     mWindowSubclassed = false;
 }
 
 bool Surface::checkForOutOfDateSwapChain()
diff --git a/gfx/angle/src/libGLESv2/VertexDataManager.cpp b/gfx/angle/src/libGLESv2/VertexDataManager.cpp
--- a/gfx/angle/src/libGLESv2/VertexDataManager.cpp
+++ b/gfx/angle/src/libGLESv2/VertexDataManager.cpp
@@ -50,24 +50,24 @@ VertexDataManager::~VertexDataManager()
     delete mStreamingBuffer;
 
     for (int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
     {
         delete mCurrentValueBuffer[i];
     }
 }
 
-UINT VertexDataManager::writeAttributeData(ArrayVertexBuffer *vertexBuffer, GLint start, GLsizei count, const VertexAttribute &attribute)
+std::size_t VertexDataManager::writeAttributeData(ArrayVertexBuffer *vertexBuffer, GLint start, GLsizei count, const VertexAttribute &attribute)
 {
     Buffer *buffer = attribute.mBoundBuffer.get();
 
     int inputStride = attribute.stride();
     int elementSize = attribute.typeSize();
     const FormatConverter &converter = formatConverter(attribute);
-    UINT streamOffset = 0;
+    std::size_t streamOffset = 0;
 
     void *output = NULL;
     
     if (vertexBuffer)
     {
         output = vertexBuffer->map(attribute, spaceRequired(attribute, count), &streamOffset);
     }
 
@@ -198,17 +198,17 @@ GLenum VertexDataManager::prepareVertexD
                     return GL_INVALID_OPERATION;
                 }
 
                 const FormatConverter &converter = formatConverter(attribs[i]);
 
                 StaticVertexBuffer *staticBuffer = buffer ? buffer->getStaticVertexBuffer() : NULL;
                 ArrayVertexBuffer *vertexBuffer = staticBuffer ? staticBuffer : static_cast<ArrayVertexBuffer*>(mStreamingBuffer);
 
-                UINT streamOffset = -1;
+                std::size_t streamOffset = -1;
 
                 if (staticBuffer)
                 {
                     streamOffset = staticBuffer->lookupAttribute(attribs[i]);
 
                     if (streamOffset == -1)
                     {
                         // Convert the entire buffer
@@ -666,17 +666,17 @@ void StreamingVertexBuffer::reserveRequi
 StaticVertexBuffer::StaticVertexBuffer(IDirect3DDevice9 *device) : ArrayVertexBuffer(device, 0, D3DUSAGE_WRITEONLY)
 {
 }
 
 StaticVertexBuffer::~StaticVertexBuffer()
 {
 }
 
-void *StaticVertexBuffer::map(const VertexAttribute &attribute, std::size_t requiredSpace, UINT *streamOffset)
+void *StaticVertexBuffer::map(const VertexAttribute &attribute, std::size_t requiredSpace, std::size_t *streamOffset)
 {
     void *mapPtr = NULL;
 
     if (mVertexBuffer)
     {
         HRESULT result = mVertexBuffer->Lock(mWritePosition, requiredSpace, &mapPtr, 0);
         
         if (FAILED(result))
diff --git a/gfx/angle/src/libGLESv2/VertexDataManager.h b/gfx/angle/src/libGLESv2/VertexDataManager.h
--- a/gfx/angle/src/libGLESv2/VertexDataManager.h
+++ b/gfx/angle/src/libGLESv2/VertexDataManager.h
@@ -30,17 +30,17 @@ struct TranslatedAttribute
     UINT stride;   // 0 means not to advance the read pointer at all
 
     IDirect3DVertexBuffer9 *vertexBuffer;
 };
 
 class VertexBuffer
 {
   public:
-    VertexBuffer(IDirect3DDevice9 *device, UINT size, DWORD usageFlags);
+    VertexBuffer(IDirect3DDevice9 *device, std::size_t size, DWORD usageFlags);
     virtual ~VertexBuffer();
 
     void unmap();
 
     IDirect3DVertexBuffer9 *getBuffer() const;
 
   protected:
     IDirect3DDevice9 *const mDevice;
@@ -55,60 +55,60 @@ class ConstantVertexBuffer : public Vert
   public:
     ConstantVertexBuffer(IDirect3DDevice9 *device, float x, float y, float z, float w);
     ~ConstantVertexBuffer();
 };
 
 class ArrayVertexBuffer : public VertexBuffer
 {
   public:
-    ArrayVertexBuffer(IDirect3DDevice9 *device, UINT size, DWORD usageFlags);
+    ArrayVertexBuffer(IDirect3DDevice9 *device, std::size_t size, DWORD usageFlags);
     ~ArrayVertexBuffer();
 
-    UINT size() const { return mBufferSize; }
-    virtual void *map(const VertexAttribute &attribute, UINT requiredSpace, UINT *streamOffset) = 0;
+    std::size_t size() const { return mBufferSize; }
+    virtual void *map(const VertexAttribute &attribute, std::size_t requiredSpace, std::size_t *streamOffset) = 0;
     virtual void reserveRequiredSpace() = 0;
     void addRequiredSpace(UINT requiredSpace);
 
   protected:
-    UINT mBufferSize;
-    UINT mWritePosition;
-    UINT mRequiredSpace;
+    std::size_t mBufferSize;
+    std::size_t mWritePosition;
+    std::size_t mRequiredSpace;
 };
 
 class StreamingVertexBuffer : public ArrayVertexBuffer
 {
   public:
-    StreamingVertexBuffer(IDirect3DDevice9 *device, UINT initialSize);
+    StreamingVertexBuffer(IDirect3DDevice9 *device, std::size_t initialSize);
     ~StreamingVertexBuffer();
 
-    void *map(const VertexAttribute &attribute, UINT requiredSpace, UINT *streamOffset);
+    void *map(const VertexAttribute &attribute, std::size_t requiredSpace, std::size_t *streamOffset);
     void reserveRequiredSpace();
 };
 
 class StaticVertexBuffer : public ArrayVertexBuffer
 {
   public:
     explicit StaticVertexBuffer(IDirect3DDevice9 *device);
     ~StaticVertexBuffer();
 
-    void *map(const VertexAttribute &attribute, UINT requiredSpace, UINT *streamOffset);
+    void *map(const VertexAttribute &attribute, std::size_t requiredSpace, std::size_t *streamOffset);
     void reserveRequiredSpace();
 
     UINT lookupAttribute(const VertexAttribute &attribute);   // Returns the offset into the vertex buffer, or -1 if not found
 
   private:
     struct VertexElement
     {
         GLenum type;
         GLint size;
         bool normalized;
         int attributeOffset;
 
-        UINT streamOffset;
+        std::size_t streamOffset;
     };
 
     std::vector<VertexElement> mCache;
 };
 
 class VertexDataManager
 {
   public:
@@ -117,18 +117,18 @@ class VertexDataManager
 
     void dirtyCurrentValue(int index) { mDirtyCurrentValue[index] = true; }
 
     GLenum prepareVertexData(GLint start, GLsizei count, TranslatedAttribute *outAttribs);
 
   private:
     DISALLOW_COPY_AND_ASSIGN(VertexDataManager);
 
-    UINT spaceRequired(const VertexAttribute &attrib, std::size_t count) const;
-    UINT writeAttributeData(ArrayVertexBuffer *vertexBuffer, GLint start, GLsizei count, const VertexAttribute &attribute);
+    std::size_t spaceRequired(const VertexAttribute &attrib, std::size_t count) const;
+    std::size_t writeAttributeData(ArrayVertexBuffer *vertexBuffer, GLint start, GLsizei count, const VertexAttribute &attribute);
 
     Context *const mContext;
     IDirect3DDevice9 *const mDevice;
 
     StreamingVertexBuffer *mStreamingBuffer;
 
     bool mDirtyCurrentValue[MAX_VERTEX_ATTRIBS];
     ConstantVertexBuffer *mCurrentValueBuffer[MAX_VERTEX_ATTRIBS];