Throttle rendering pipeline for invisible frames

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 "config.h"
 #include "core/page/PageAnimator.h"
 
 #include "core/animation/DocumentAnimations.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 26 matching lines @@
     RefPtrWillBeRawPtr<PageAnimator> protector(this);
     TemporaryChange<bool> servicing(m_servicingAnimations, true);
 
     WillBeHeapVector<RefPtrWillBeMember<Document>> documents;
     for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
         if (frame->isLocalFrame())
             documents.append(toLocalFrame(frame)->document());
     }
 
     for (auto& document : documents) {
+        DocumentAnimations::updateAnimationTimingForAnimationFrame(*document, monotonicAnimationStartTime);
         if (document->view()) {
+            if (document->view()->shouldThrottleRenderingPipeline())
+                continue;
             document->view()->scrollableArea()->serviceScrollAnimations(monotonicAnimationStartTime);
 
             if (const FrameView::ScrollableAreaSet* animatingScrollableAreas = document->view()->animatingScrollableAreas()) {
                 // Iterate over a copy, since ScrollableAreas may deregister
                 // themselves during the iteration.
                 Vector<ScrollableArea*> animatingScrollableAreasCopy;
                 copyToVector(*animatingScrollableAreas, animatingScrollableAreasCopy);
                 for (ScrollableArea* scrollableArea : animatingScrollableAreasCopy)
                     scrollableArea->serviceScrollAnimations(monotonicAnimationStartTime);
             }
         }
-        DocumentAnimations::updateAnimationTimingForAnimationFrame(*document, monotonicAnimationStartTime);
         SVGDocumentExtensions::serviceOnAnimationFrame(*document, monotonicAnimationStartTime);
         document->serviceScriptedAnimations(monotonicAnimationStartTime);

[ojan, 2015/10/13 23:31:29]

I think you want to skip these two lines as well when throttling. I'm curious if
we want to execute this code for a document that doesn't have a view. Maybe add
a TODO to investigate that? I don't want to block this patch on figuring that
out.

[Sami, 2015/10/14 16:52:11]

These two are already being skipped thanks to the "continue" above. It's not
very clear from the way the code is laid out -- but I don't have good ideas for
making it more obvious assuming these two also need to be run when we don't have
a view.

Added a TODO for finding out if these should also be skipped when we don't have
a view.

     }
 
 #if ENABLE(OILPAN)
     // TODO(esprehn): Why is this here? It doesn't make sense to explicitly
     // clear a stack allocated vector.
     documents.clear();
 #endif
 }
 
 void PageAnimator::scheduleVisualUpdate(LocalFrame* frame)
@@ skipping 12 matching lines @@
 }
 
 void PageAnimator::updateLayoutAndStyleForPainting(LocalFrame* rootFrame)
 {
     RefPtrWillBeRawPtr<FrameView> view = rootFrame->view();
 
     TemporaryChange<bool> servicing(m_updatingLayoutAndStyleForPainting, true);
 
     // setFrameRect may have the side-effect of causing existing page layout to
     // be invalidated, so layout needs to be called last.
-    view->updateAllLifecyclePhases();
+    view->updateAllLifecyclePhases(DocumentLifecycle::ThrottlingMode::Allow);
 }
 
 }