Disabled pinch zooming in non-browser Aura windows.

content/public/browser/web_contents_delegate.h

Index: content/public/browser/web_contents_delegate.h
diff --git a/content/public/browser/web_contents_delegate.h b/content/public/browser/web_contents_delegate.h
index 5ee14747abd85fa2e77afcd5a1bc94aba1af82aa..3515d89a67d45bb6a9362136fd00fb7eafc403d8 100644
--- a/content/public/browser/web_contents_delegate.h
+++ b/content/public/browser/web_contents_delegate.h
@@ -55,6 +55,7 @@ class Size;
 }
 
 namespace blink {
+class WebGestureEvent;
 class WebLayer;
 struct WebWindowFeatures;
 }
@@ -258,6 +259,15 @@ class CONTENT_EXPORT WebContentsDelegate {
   // pressed, or a touch-gesture begins).
   virtual void HandlePointerActivate() {}
 
+  // Allows delegates to handle gesture events before sending to the renderer.
+  // Returns true if the |event| was handled and thus shouldn't be processed
+  // by the renderer's event handler. Note that the touch events that create
+  // the gesture are always passed to the renderer since the gesture is created
+  // and dispatched after the touches return without being "preventDefault()"ed.
+  virtual bool PreHandleGestureEvent(
+      WebContents* source,
+      const blink::WebGestureEvent& event);
+
   virtual void HandleGestureBegin() {}
   virtual void HandleGestureEnd() {}