Add initial CC support for scroll-blocks-on

content/renderer/input/input_handler_proxy.cc

 // Copyright 2013 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 "content/renderer/input/input_handler_proxy.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ skipping 540 matching lines @@
       break;
   }
   return DID_NOT_HANDLE;
 }
 
 InputHandlerProxy::EventDisposition InputHandlerProxy::HandleTouchStart(
     const blink::WebTouchEvent& touch_event) {
   for (size_t i = 0; i < touch_event.touchesLength; ++i) {
     if (touch_event.touches[i].state != WebTouchPoint::StatePressed)
       continue;
-    if (input_handler_->HaveTouchEventHandlersAt(
+    if (input_handler_->DoTouchEventsBlockScrollAt(
             gfx::Point(touch_event.touches[i].position.x,
                        touch_event.touches[i].position.y))) {
+      // TODO(rbyers): We should consider still sending the touch events to
+      // main asynchronously (crbug.com/347272).

[jdduke (slow), 2015/02/03 16:43:35]

Might be nice to have a more specific bug for this behavior, but not necessary.

[Rick Byers, 2015/02/05 04:35:53]

Yeah, good idea.  At some point we might want to weigh the cost/benefit tradeoff
of doing that - good to have one bug to track the debate.  Done.

       return DID_NOT_HANDLE;
     }
   }
   return DROP_EVENT;
 }
 
 bool InputHandlerProxy::FilterInputEventForFlingBoosting(
     const WebInputEvent& event) {
   if (!WebInputEvent::isGestureEventType(event.type))
     return false;
@@ skipping 366 matching lines @@
   // trigger a scroll, e.g., with a trivial time delta between fling updates.
   // Return true in this case to prevent early fling termination.
   if (std::abs(clipped_increment.width) < kScrollEpsilon &&
       std::abs(clipped_increment.height) < kScrollEpsilon)
     return true;
 
   return did_scroll;
 }
 
 }  // namespace content