Navigation transitions: Add finch trial for navigation transitions.

content/child/runtime_features.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/runtime_features.h"
 
 #include "base/command_line.h"
 #include "content/common/content_switches_internal.h"
 #include "content/public/common/content_switches.h"
 #include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
 #include "ui/native_theme/native_theme_switches.h"
 
 #if defined(OS_ANDROID)
 #include <cpu-features.h>
 #include "base/android/build_info.h"
+#include "base/metrics/field_trial.h"
 #include "media/base/android/media_codec_bridge.h"
 #endif
 
 using blink::WebRuntimeFeatures;
 
 namespace content {
 
 static void SetRuntimeFeatureDefaultsForPlatform() {
 #if defined(OS_ANDROID)
   // MSE/EME implementation needs Android MediaCodec API.
@@ skipping 20 matching lines @@
   // Android does not yet support the Web Notification API. crbug.com/115320
   WebRuntimeFeatures::enableNotifications(false);
   // Android does not yet support SharedWorker. crbug.com/154571
   WebRuntimeFeatures::enableSharedWorker(false);
   // Android does not yet support NavigatorContentUtils.
   WebRuntimeFeatures::enableNavigatorContentUtils(false);
   WebRuntimeFeatures::enableTouchIconLoading(true);
   WebRuntimeFeatures::enableOrientationEvent(true);
   WebRuntimeFeatures::enableFastMobileScrolling(true);
   WebRuntimeFeatures::enableMediaCapture(true);
+  // If navigation transitions gets activated via field trial, enable it in
+  // blink. We don't set this to false in case the user has manually enabled
+  // the feature via experimental web platform features.
+  if (base::FieldTrialList::FindFullName("NavigationTransitions") == "Enabled")
+    WebRuntimeFeatures::enableNavigationTransitions(true);
 #else
   WebRuntimeFeatures::enableNavigatorContentUtils(true);
 #endif  // defined(OS_ANDROID)
 }
 
 void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
     const CommandLine& command_line) {
   if (command_line.HasSwitch(switches::kEnableExperimentalWebPlatformFeatures))
     WebRuntimeFeatures::enableExperimentalFeatures(true);
 
@@ skipping 85 matching lines @@
     WebRuntimeFeatures::enableBleedingEdgeFastPaths(true);
 
   if (command_line.HasSwitch(switches::kEnablePreciseMemoryInfo))
     WebRuntimeFeatures::enablePreciseMemoryInfo(true);
 
   if (command_line.HasSwitch(switches::kEnableLayerSquashing))
     WebRuntimeFeatures::enableLayerSquashing(true);
 }
 
 }  // namespace content