Do not set touch region on PageOverlay layer.

With new touch hit testing in compositor, which looks through all
the layers hitting the point, we don't need touch regions on overlay
layer anymore.

Note, that we still need main-thread scrolling to stay in sync with
page contents.

BUG=304271

Review URL: https://codereview.chromium.org/305383002

git-svn-id: svn://svn.chromium.org/blink/trunk@175578 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/fast/events/touch/compositor-touch-hit-rects-global-expected.txt

@@ -6,6 +6,6 @@ html: #document (0, 0, 785, 2000)
 
 body: #document (0, 0, 785, 2000)
 
-webPageOverlay: [unknown-node] (0, 0, 2147483648, 2147483648)
+webPageOverlay: no rects
 
 

third_party/WebKit/Source/web/PageOverlay.cpp

@@ -122,14 +122,9 @@ void PageOverlay::update()
         if (WebCore::Page* page = m_viewImpl->page())
             page->inspectorController().willAddPageOverlay(m_layer.get());
 
-        // Compositor hit-testing does not know how to deal with layers that may be
-        // transparent to events (see http://crbug.com/269598). So require
-        // scrolling and touches on this layer to go to the main thread.
+        // This is required for contents of overlay to stay in sync with the page while scrolling.
         WebLayer* platformLayer = m_layer->platformLayer();
         platformLayer->setShouldScrollOnMainThread(true);
-        WebVector<WebRect> webRects(static_cast<size_t>(1));
-        webRects[0] = WebRect(0, 0, INT_MAX, INT_MAX);
-        platformLayer->setTouchEventHandlerRegion(webRects);
     }
 
     FloatSize size(m_viewImpl->size());