Media element: avoid v8 allocations in hasPendingActivity().

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index c812addeafe4fcdf05b0df3990075b6e0e1ce6d5..f6c5b571db9c242e726b7444d4f0e96b68836ff6 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -92,6 +92,7 @@
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackAvailability.h"
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackClient.h"
 #include "public/platform/modules/remoteplayback/WebRemotePlaybackState.h"
+#include "wtf/AutoReset.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/MathExtras.h"
 #include "wtf/PtrUtil.h"
@@ -3458,9 +3459,16 @@ bool HTMLMediaElement::hasPendingActivity() const {
   if (m_networkState == kNetworkLoading)
     return true;
 
-  // When playing or if playback may continue, timeupdate events may be fired.
-  if (couldPlayIfEnoughData())
-    return true;
+  {
+    // Disable potential updating of playback position, as that will
+    // require v8 allocations; not allowed while GCing
+    // (hasPendingActivity() is called during a v8 GC.)
+    AutoReset<bool> scope(&m_officialPlaybackPositionNeedsUpdate, false);
+
+    // When playing or if playback may continue, timeupdate events may be fired.
+    if (couldPlayIfEnoughData())
+      return true;
+  }
 
   // When the seek finishes timeupdate and seeked events will be fired.
   if (m_seeking)