Disabled pinch zooming in non-browser Aura windows.

ui/web_dialogs/web_dialog_web_contents_delegate.h

Index: ui/web_dialogs/web_dialog_web_contents_delegate.h
diff --git a/ui/web_dialogs/web_dialog_web_contents_delegate.h b/ui/web_dialogs/web_dialog_web_contents_delegate.h
index 65d514ae3b761254a0e124b0680b75d03fbf3469..50b4a65858b8115dcd9099a02bdd07a0ba3599b0 100644
--- a/ui/web_dialogs/web_dialog_web_contents_delegate.h
+++ b/ui/web_dialogs/web_dialog_web_contents_delegate.h
@@ -56,7 +56,6 @@ class WEB_DIALOGS_EXPORT WebDialogWebContentsDelegate
   virtual content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) OVERRIDE;
-
   virtual void AddNewContents(content::WebContents* source,
                               content::WebContents* new_contents,
                               WindowOpenDisposition disposition,
@@ -65,6 +64,9 @@ class WEB_DIALOGS_EXPORT WebDialogWebContentsDelegate
                               bool* was_blocked) OVERRIDE;
   virtual bool IsPopupOrPanel(
       const content::WebContents* source) const OVERRIDE;
+  virtual bool PreHandleGestureEvent(
+      content::WebContents* source,
+      const blink::WebGestureEvent& event) OVERRIDE;
 
  private:
   // Weak pointer.  Always an original profile.