Enable partial recording if slimmingPaintDisplayItemCache is enabled

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 77df05fdfd1039d7a2df2251656fa5e7ebe07b7b..96c6f1b0ecce132fc5e7ae32578baca9dbf4700e 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -39,6 +39,7 @@
 #include "third_party/WebKit/public/platform/WebSelectionBound.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/WebKit/public/web/WebKit.h"
+#include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
 #include "third_party/WebKit/public/web/WebWidget.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gfx/hud_font.h"
@@ -195,7 +196,12 @@ void RenderWidgetCompositor::Initialize() {
       !compositor_deps_->IsElasticOverscrollEnabled();
   settings.accelerated_animation_enabled =
       !cmd->HasSwitch(cc::switches::kDisableThreadedAnimation);
-  settings.use_display_lists = cmd->HasSwitch(switches::kEnableSlimmingPaint);
+  if (cmd->HasSwitch(switches::kEnableSlimmingPaint)) {
+    settings.use_display_lists = true;
+    blink::WebRuntimeFeatures::enableSlimmingPaint(true);

[Xianzhu, 2015/02/12 22:33:49]

This is needed because slimmingPaintDisplayItemCacheEnabled will be always false
before enableSlimmingPaint is called. Though we do the same in RenderViewImpl,
it's later than here.

+    settings.record_full_layer =
+        !blink::WebRuntimeFeatures::slimmingPaintDisplayItemCacheEnabled();
+  }
 
   settings.default_tile_size = CalculateDefaultTileSize();
   if (cmd->HasSwitch(switches::kDefaultTileWidth)) {