Animations: Implement runtime flag for enabling compositor animation timelines.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 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/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 198 matching lines @@
   settings.report_overscroll_only_for_scrollable_axes =
       !compositor_deps_->IsElasticOverscrollEnabled();
   settings.accelerated_animation_enabled =
       !cmd->HasSwitch(cc::switches::kDisableThreadedAnimation);
   if (cmd->HasSwitch(switches::kEnableSlimmingPaint)) {
     settings.use_display_lists = true;
     blink::WebRuntimeFeatures::enableSlimmingPaint(true);
     settings.record_full_layer =
         !blink::WebRuntimeFeatures::slimmingPaintDisplayItemCacheEnabled();
   }
+  if (cmd->HasSwitch(switches::kEnableCompositorAnimationTimelines)) {
+    settings.use_compositor_animation_timelines = true;
+    blink::WebRuntimeFeatures::enableCompositorAnimationTimelines(true);
+  }
 
   settings.default_tile_size = CalculateDefaultTileSize();
   if (cmd->HasSwitch(switches::kDefaultTileWidth)) {
     int tile_width = 0;
     GetSwitchValueAsInt(*cmd,
                         switches::kDefaultTileWidth,
                         1,
                         std::numeric_limits<int>::max(),
                         &tile_width);
     settings.default_tile_size.set_width(tile_width);
@@ skipping 678 matching lines @@
   cc::ContextProvider* provider =
       compositor_deps_->GetSharedMainThreadContextProvider();
   // provider can be NULL after the GPU process crashed enough times and we
   // don't want to restart it any more (falling back to software).
   if (!provider)
     return;
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content