Delay SVGImage animations reset while being updated.

third_party/WebKit/Source/core/svg/graphics/SVGImageChromeClient.cpp

Index: third_party/WebKit/Source/core/svg/graphics/SVGImageChromeClient.cpp
diff --git a/third_party/WebKit/Source/core/svg/graphics/SVGImageChromeClient.cpp b/third_party/WebKit/Source/core/svg/graphics/SVGImageChromeClient.cpp
index 808438d18b3f2b60fae56ea0b2412429c4fdf910..699d0891a16f1380983d9b815f7d6969b6f72907 100644
--- a/third_party/WebKit/Source/core/svg/graphics/SVGImageChromeClient.cpp
+++ b/third_party/WebKit/Source/core/svg/graphics/SVGImageChromeClient.cpp
@@ -101,11 +101,17 @@ void SVGImageChromeClient::animationTimerFired(Timer<SVGImageChromeClient>*)
     // images can't have any so we assert there's no script.
     ScriptForbiddenScope forbidScript;
 
-    // The calls below may trigger GCs, so set up the required persistent
-    // reference on the ImageResource which owns this SVGImage. By transitivity,
-    // that will keep this SVGImageChromeClient object alive.
-    Persistent<ImageObserver> protect(m_image->getImageObserver());
-    m_image->frameView()->page()->animator().serviceScriptedAnimations(monotonicallyIncreasingTime());
+    // The call below may trigger GCs, so set up the required reference
+    // to the ImageObserver (an ImageResource) which owns this SVGImage.
+    // By transitivity, that will keep this SVGImageChromeClient object alive.
+    //
+    // The update scope will additionally prevent the GCs from indirectly
+    // triggering animations reset over m_image should the ImageResource become
+    // otherwise unreferenced.
+    {
+        SVGImage::UpdateAnimationScope scope(m_image);
+        m_image->frameView()->page()->animator().serviceScriptedAnimations(monotonicallyIncreasingTime());
+    }
     m_image->frameView()->updateAllLifecyclePhases();
 }