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// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/preloading/prerender/prerender_features.h"
#include "content/public/common/content_features.h"
namespace features {
// Allows activation in background tab. For now, this is used only on web
// platform tests on macOS to run activation with target hint tests that have
// race conditions between visibility change and activation start on a prerender
// WebContents. Note that this issue does not happen on browser_tests, so this
// could be specific to WPT setup.
// TODO(crbug.com/40249964): Allow activation in background by default.
BASE_FEATURE(kPrerender2AllowActivationInBackground,
"Prerender2AllowActivationInBackground",
base::FEATURE_DISABLED_BY_DEFAULT);
// Enables fallback from prerender to prefetch for Speculation Rules.
// See https://crbug.com/342089123 for more details.
//
// Effects:
//
// - Use code paths for prefetch/prerender integration. (The effect of
// `kPrefetchPrerenderIntegration`).
// - Trigger prefetch ahead of prerender.
BASE_FEATURE(kPrerender2FallbackPrefetchSpecRules,
"Prerender2FallbackPrefetchSpecRules",
base::FEATURE_DISABLED_BY_DEFAULT);
constexpr base::FeatureParam<Prerender2FallbackPrefetchReusablePolicy>::Option
kPrerender2FallbackPrefetchReusablePolicyOptions[] = {
{Prerender2FallbackPrefetchReusablePolicy::kNotUse, "NotUse"},
{Prerender2FallbackPrefetchReusablePolicy::
kUseIfIsLikelyAheadOfPrerender,
"UseIfIsLikelyAheadOfPrerender"},
{Prerender2FallbackPrefetchReusablePolicy::kUseAlways, "UseAlways"},
};
const base::FeatureParam<Prerender2FallbackPrefetchReusablePolicy>
kPrerender2FallbackPrefetchReusablePolicy{
&kPrerender2FallbackPrefetchSpecRules,
"kPrerender2FallbackPrefetchReusablePolicy",
Prerender2FallbackPrefetchReusablePolicy::kNotUse,
&kPrerender2FallbackPrefetchReusablePolicyOptions};
const base::FeatureParam<size_t> kPrerender2FallbackBodySizeLimit{
&kPrerender2FallbackPrefetchSpecRules, "kPrerender2FallbackBodySizeLimit",
65536};
const base::FeatureParam<bool>
kPrerender2FallbackPrefetchUseBlockUntilHeadTimetout{
&kPrerender2FallbackPrefetchSpecRules,
"kPrerender2FallbackPrefetchUseBlockUntilHeadTimetout", true};
constexpr base::FeatureParam<Prerender2FallbackPrefetchSchedulerPolicy>::Option
kPrerender2FallbackPrefetchSchedulerPolicyOptios[] = {
{Prerender2FallbackPrefetchSchedulerPolicy::kNotUse, "NotUse"},
{Prerender2FallbackPrefetchSchedulerPolicy::kPrioritize, "Prioritize"},
{Prerender2FallbackPrefetchSchedulerPolicy::kBurst, "Burst"},
};
const base::FeatureParam<Prerender2FallbackPrefetchSchedulerPolicy>
kPrerender2FallbackPrefetchSchedulerPolicy{
&kPrerender2FallbackPrefetchSpecRules,
"kPrerender2FallbackPrefetchSchedulerPolicy",
Prerender2FallbackPrefetchSchedulerPolicy::kNotUse,
&kPrerender2FallbackPrefetchSchedulerPolicyOptios};
BASE_FEATURE(kPrerender2NoVarySearch,
"Prerender2NoVarySearch",
base::FEATURE_ENABLED_BY_DEFAULT);
const base::FeatureParam<int>
kPrerender2NoVarySearchWaitForHeadersTimeoutEagerPrerender{
&kPrerender2NoVarySearch, "wait_for_headers_timeout_eager_prerender",
1000};
const base::FeatureParam<int>
kPrerender2NoVarySearchWaitForHeadersTimeoutModeratePrerender{
&kPrerender2NoVarySearch, "wait_for_headers_timeout_moderate_prerender",
0};
const base::FeatureParam<int>
kPrerender2NoVarySearchWaitForHeadersTimeoutConservativePrerender{
&kPrerender2NoVarySearch,
"wait_for_headers_timeout_conservative_prerender", 0};
const base::FeatureParam<int>
kPrerender2NoVarySearchWaitForHeadersTimeoutForEmbedders{
&kPrerender2NoVarySearch, "wait_for_headers_timeout_embedders", 1000};
// If enabled, suppresses prerendering on slow network.
BASE_FEATURE(kSuppressesPrerenderingOnSlowNetwork,
"SuppressesPrerenderingOnSlowNetwork",
base::FEATURE_DISABLED_BY_DEFAULT);
// Regarding how this number was chosen, see the design doc linked from
// crbug.com/350519234.
const base::FeatureParam<base::TimeDelta>
kSuppressesPrerenderingOnSlowNetworkThreshold{
&kSuppressesPrerenderingOnSlowNetwork,
"slow_network_threshold_for_prerendering", base::Milliseconds(208)};
// If enabled, disallows non-trustworthy plaintext HTTP prerendering.
// See https://crbug.com/340895233 for more details.
BASE_FEATURE(kPrerender2DisallowNonTrustworthyHttp,
"Prerender2DisallowNonTrustworthyHttp",
base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kPrerender2WarmUpCompositorForImmediate,
"Prerender2WarmUpCompositorForImmediate",
base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kPrerender2WarmUpCompositorForNonImmediate,
"Prerender2WarmUpCompositorForNonImmediate",
base::FEATURE_DISABLED_BY_DEFAULT);
bool UsePrefetchPrerenderIntegration() {
return base::FeatureList::IsEnabled(
features::kPrerender2FallbackPrefetchSpecRules) ||
base::FeatureList::IsEnabled(features::kPrefetchPrerenderIntegration);
}
} // namespace features
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