Check whether a touch point hits touch event handler regions in root layer

cc/layer_tree_host_common.cc

 // Copyright 2011 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 "cc/layer_tree_host_common.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "cc/layer.h"
@@ skipping 981 matching lines @@
     typedef LayerIterator<LayerImpl, std::vector<LayerImpl*>, RenderSurfaceImpl, LayerIteratorActions::FrontToBack> LayerIteratorType;
     LayerIteratorType end = LayerIteratorType::end(&renderSurfaceLayerList);
 
     for (LayerIteratorType it = LayerIteratorType::begin(&renderSurfaceLayerList); it != end; ++it) {
         // We don't want to consider renderSurfaces for hit testing.
         if (!it.representsItself())
             continue;
 
         LayerImpl* currentLayer = (*it);
 
-        if (currentLayer->touchEventHandlerRegion().IsEmpty())
-            continue;
-
-        if (!pointHitsRegion(screenSpacePoint, currentLayer->screenSpaceTransform(), currentLayer->touchEventHandlerRegion(), currentLayer->contentsScaleX(), currentLayer->contentsScaleY()))
-            continue;
-
-        // At this point, we think the point does hit the touch event handler region on the layer, but we need to walk up
-        // the parents to ensure that the layer was not clipped in such a way that the
-        // hit point actually should not hit the layer.
-        if (pointIsClippedBySurfaceOrClipRect(screenSpacePoint, currentLayer))
+        if (!layerHasTouchEventHandlersAt(screenSpacePoint, currentLayer))
             continue;
 
         foundLayer = currentLayer;
         break;
     }
 
     // This can potentially return 0, which means the screenSpacePoint did not successfully hit test any layers, not even the root layer.
     return foundLayer;
 }
 
+bool LayerTreeHostCommon::layerHasTouchEventHandlersAt(const gfx::PointF& screenSpacePoint, LayerImpl* layerImpl) {
+  if (layerImpl->touchEventHandlerRegion().IsEmpty())
+      return false;
+
+  if (!pointHitsRegion(screenSpacePoint, layerImpl->screenSpaceTransform(), layerImpl->touchEventHandlerRegion(), layerImpl->contentsScaleX(), layerImpl->contentsScaleY()))
+     return false;;
+
+  // At this point, we think the point does hit the touch event handler region on the layer, but we need to walk up
+  // the parents to ensure that the layer was not clipped in such a way that the
+  // hit point actually should not hit the layer.
+  if (pointIsClippedBySurfaceOrClipRect(screenSpacePoint, layerImpl))
+     return false;
+
+  return true;
+}
 }  // namespace cc