Notify Blink to suppress frame requests during BeginMainFrame

third_party/WebKit/Source/core/page/PageAnimator.cpp

 // Copyright 2014 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 "core/page/PageAnimator.h"
 
 #include "core/animation/DocumentAnimations.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/page/ChromeClient.h"
@@ skipping 55 matching lines @@
       }
       SVGDocumentExtensions::serviceOnAnimationFrame(*document);
     }
     // TODO(skyostil): This function should not run for documents without views.
     DocumentLifecycle::DisallowThrottlingScope noThrottlingScope(
         document->lifecycle());
     document->serviceScriptedAnimations(monotonicAnimationStartTime);
   }
 }
 
+void PageAnimator::setSuppressFrameRequestsWorkaroundFor704763Only(
+    bool suppressFrameRequests) {
+  // If we are enabling the suppression and it was already enabled then we must
+  // have missed disabling it at the end of a previous frame.
+  DCHECK(!m_suppressFrameRequestsWorkaroundFor704763Only ||

[esprehn, 2017/04/05 08:33:02]

This could be != Instead of the or I think?

[alancutter (OOO until 2018), 2017/04/05 10:04:18]

It used to be but some tests call UpdateVisualState() twice in a row inside
paint test helpers. See above comments.

+         !suppressFrameRequests);
+  m_suppressFrameRequestsWorkaroundFor704763Only = suppressFrameRequests;
+}
+
 DISABLE_CFI_PERF
 void PageAnimator::scheduleVisualUpdate(LocalFrame* frame) {
-  if (m_servicingAnimations || m_updatingLayoutAndStyleForPainting)
+  if (m_servicingAnimations || m_updatingLayoutAndStyleForPainting ||
+      m_suppressFrameRequestsWorkaroundFor704763Only) {
     return;
+  }
   m_page->chromeClient().scheduleAnimation(frame->view());
 }
 
 void PageAnimator::updateAllLifecyclePhases(LocalFrame& rootFrame) {
   FrameView* view = rootFrame.view();
   AutoReset<bool> servicing(&m_updatingLayoutAndStyleForPainting, true);
   view->updateAllLifecyclePhases();
 }
 
 }  // namespace blink