Report correct touch hit rects for fullscreen HTML5 video on Android

Source/core/page/scrolling/ScrollingCoordinator.cpp

Index: Source/core/page/scrolling/ScrollingCoordinator.cpp
diff --git a/Source/core/page/scrolling/ScrollingCoordinator.cpp b/Source/core/page/scrolling/ScrollingCoordinator.cpp
index 44e1df16a7fe1d7cd0d587a3403a4ccef6081f5b..3afc5ea442da0dd41ac2c7db92ea6bbcd0207077 100644
--- a/Source/core/page/scrolling/ScrollingCoordinator.cpp
+++ b/Source/core/page/scrolling/ScrollingCoordinator.cpp
@@ -778,7 +778,7 @@ Region ScrollingCoordinator::computeShouldHandleScrollGestureOnMainThreadRegion(
     return shouldHandleScrollGestureOnMainThreadRegion;
 }
 
-static void accumulateDocumentTouchEventTargetRects(LayerHitTestRects& rects, const Document* document)
+static void accumulateDocumentTouchEventTargetRects(LayerHitTestRects& rects, Document* document)
 {
     ASSERT(document);
     if (!document->touchEventTargets())
@@ -790,7 +790,12 @@ static void accumulateDocumentTouchEventTargetRects(LayerHitTestRects& rects, co
     // then we can quickly mark the entire document and skip looking at any other handlers.
     // Note that technically a handler on the body doesn't cover the whole document, but it's
     // reasonable to be conservative and report the whole document anyway.
-    for (TouchEventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter) {
+    //
+    // Fullscreen HTML5 video on Android is implemented by replacing the root cc:layer with the
+    // video layer so doing this optimization causes the compositor to think that there are no
+    // handlers when in full screen therefore skip it.
+    bool inFullscreenOnAndroid = RuntimeEnabledFeatures::overlayFullscreenVideoEnabled() && RenderLayerCompositor::findFullscreenVideoRenderer(*document);

[abarth-chromium, 2014/06/07 09:06:03]

It's inefficient to call findFullscreenVideoRenderer more than once per frame. 
Can the RenderLayerCompositor and this code share the information about whether
we're inFullscreenOnAndroid instead of each computing it separately.

Also, please don't refer to Android in the variable name.  In principle, this
can happen whenever RuntimeEnabledFeatures::overlayFullscreenVideoEnabled is
true, regardless of whether we're on Android.

+    for (TouchEventTargetSet::const_iterator iter = targets->begin(); !inFullscreenOnAndroid && iter != targets->end(); ++iter) {
         Node* target = iter->key;
         if (target == document || target == document->documentElement() || target == document->body()) {
             if (RenderView* rendererView = document->renderView()) {
@@ -801,12 +806,11 @@ static void accumulateDocumentTouchEventTargetRects(LayerHitTestRects& rects, co
     }
 
     for (TouchEventTargetSet::const_iterator iter = targets->begin(); iter != targets->end(); ++iter) {
-        const Node* target = iter->key;
+        Node* target = iter->key;
         if (!target->inDocument())
             continue;
 
-        if (target->isDocumentNode()) {
-            ASSERT(target != document);
+        if (target->isDocumentNode() && target != document) {
             accumulateDocumentTouchEventTargetRects(rects, toDocument(target));
         } else if (RenderObject* renderer = target->renderer()) {
             // If the set also contains one of our ancestor nodes then processing