Make OffscreenCanvas animation in sync with its placeholder canvas's parent frame rate

third_party/WebKit/Source/web/ChromeClientImpl.cpp

Index: third_party/WebKit/Source/web/ChromeClientImpl.cpp
diff --git a/third_party/WebKit/Source/web/ChromeClientImpl.cpp b/third_party/WebKit/Source/web/ChromeClientImpl.cpp
index c41e1114225fb6c73a49dd6c7b2519215080ad7f..617bc5e4a4da7982c3b25631ad4414ad4487db8d 100644
--- a/third_party/WebKit/Source/web/ChromeClientImpl.cpp
+++ b/third_party/WebKit/Source/web/ChromeClientImpl.cpp
@@ -51,6 +51,7 @@
 #include "core/layout/compositing/CompositedSelection.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FrameLoadRequest.h"
+#include "core/page/ChromeClient.h"
 #include "core/page/Page.h"
 #include "core/page/PopupOpeningObserver.h"
 #include "modules/accessibility/AXObject.h"
@@ -928,6 +929,11 @@ bool ChromeClientImpl::shouldOpenModalDialogDuringPageDismissal(
   return false;
 }
 
+WebLayerTreeView* ChromeClientImpl::getWebLayerTreeView(LocalFrame* frame) {
+  WebLocalFrameImpl* webFrame = WebLocalFrameImpl::fromFrame(frame);
+  return webFrame->localRoot()->frameWidget()->getLayerTreeView();
+}
+
 void ChromeClientImpl::setEventListenerProperties(
     LocalFrame* frame,
     WebEventListenerClass eventClass,