Disabled pinch zooming in non-browser Aura windows.

content/browser/renderer_host/render_widget_host_impl.cc

 // Copyright (c) 2012 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/browser/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <set>
 #include <utility>
 
@@ skipping 984 matching lines @@
 }
 
 void RenderWidgetHostImpl::ForwardGestureEventWithLatencyInfo(
     const blink::WebGestureEvent& gesture_event,
     const ui::LatencyInfo& ui_latency) {
   TRACE_EVENT0("input", "RenderWidgetHostImpl::ForwardGestureEvent");
   // Early out if necessary, prior to performing latency logic.
   if (IgnoreInputEvents())
     return;
 
+  if (delegate_->PreHandleGestureEvent(gesture_event))
+    return;
+
   ui::LatencyInfo latency_info =
       CreateRWHLatencyInfoIfNotExist(&ui_latency, gesture_event.type);
 
   if (gesture_event.type == blink::WebInputEvent::GestureScrollUpdate) {
     latency_info.AddLatencyNumber(
         ui::INPUT_EVENT_LATENCY_SCROLL_UPDATE_RWH_COMPONENT,
         GetLatencyComponentId(),
         ++last_input_number_);
 
     // Make a copy of the INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT with a
@@ skipping 1554 matching lines @@
     }
   }
 
   // Add newly generated components into the latency info
   for (lc = new_components.begin(); lc != new_components.end(); ++lc) {
     latency_info->latency_components[lc->first] = lc->second;
   }
 }
 
 }  // namespace content