Disabled pinch zooming in non-browser Aura windows.

content/browser/renderer_host/render_widget_host_delegate.cc

Index: content/browser/renderer_host/render_widget_host_delegate.cc
diff --git a/content/browser/renderer_host/render_widget_host_delegate.cc b/content/browser/renderer_host/render_widget_host_delegate.cc
index c0493241d720009dec20c122a50c2012021a1526..09f49677e6f93e87db9b4969d065f659f77d231a 100644
--- a/content/browser/renderer_host/render_widget_host_delegate.cc
+++ b/content/browser/renderer_host/render_widget_host_delegate.cc
@@ -17,6 +17,11 @@ bool RenderWidgetHostDelegate::PreHandleWheelEvent(
   return false;
 }
 
+bool RenderWidgetHostDelegate::PreHandleGestureEvent(
+    const blink::WebGestureEvent& event) {
+  return false;
+}
+
 #if defined(OS_WIN)
 gfx::NativeViewAccessible
 RenderWidgetHostDelegate::GetParentNativeViewAccessible() {