DoubleTap Zoom support for Mobile Viewport pages

content/browser/renderer_host/frame_metadata_util.cc

 // Copyright (c) 2014 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/frame_metadata_util.h"
 
 #include "cc/output/compositor_frame_metadata.h"
 
 namespace {
 
@@ skipping 12 matching lines @@
       frame_metadata.page_scale_factor *
           frame_metadata.scrollable_viewport_size.width();
   float content_width_css = frame_metadata.root_layer_size.width();
   return content_width_css <= window_width_dip + kMobileViewportWidthEpsilon;
 }
 
 }  // namespace
 
 namespace content {
 
-bool IsMobileOptimizedFrame(const cc::CompositorFrameMetadata& frame_metadata) {
-  bool has_mobile_viewport = HasMobileViewport(frame_metadata);
+bool IsMobileOptimizedFrame(const cc::CompositorFrameMetadata& frame_metadata,
+                            bool force_enable_zoom) {
+  bool has_mobile_viewport = false;
+  if (!force_enable_zoom)
+    has_mobile_viewport = HasMobileViewport(frame_metadata);
   bool has_fixed_page_scale = HasFixedPageScale(frame_metadata);
   return has_fixed_page_scale || has_mobile_viewport;
 }
 
 }  // namespace content