Throttle rendering pipeline for invisible frames

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

Index: third_party/WebKit/Source/core/page/PageAnimator.cpp
diff --git a/third_party/WebKit/Source/core/page/PageAnimator.cpp b/third_party/WebKit/Source/core/page/PageAnimator.cpp
index 93b0e21b80b05b9b7dfee899b61685aae28cf4b0..aeb6e75de98abad467b95d9c366d3eab882adbe2 100644
--- a/third_party/WebKit/Source/core/page/PageAnimator.cpp
+++ b/third_party/WebKit/Source/core/page/PageAnimator.cpp
@@ -44,7 +44,10 @@ void PageAnimator::serviceScriptedAnimations(double monotonicAnimationStartTime)
     }
 
     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()) {
@@ -56,7 +59,6 @@ void PageAnimator::serviceScriptedAnimations(double monotonicAnimationStartTime)
                     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.

     }
@@ -91,7 +93,7 @@ void PageAnimator::updateLayoutAndStyleForPainting(LocalFrame* rootFrame)
 
     // 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);
 }
 
 }