Fix viewport computation in Mac UC

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 90 matching lines @@
 base::LazyInstance<RoutingIDWidgetMap> g_routing_id_widget_map =
     LAZY_INSTANCE_INITIALIZER;
 
 int GetInputRouterViewFlagsFromCompositorFrameMetadata(
     const cc::CompositorFrameMetadata metadata) {
   int view_flags = InputRouter::VIEW_FLAGS_NONE;
 
   if (metadata.min_page_scale_factor == metadata.max_page_scale_factor)
     view_flags |= InputRouter::FIXED_PAGE_SCALE;
 
-  const float window_width_dip =
-      std::ceil(metadata.page_scale_factor * metadata.viewport_size.width());
+  const float window_width_dip = std::ceil(
+      metadata.page_scale_factor * metadata.scrollable_viewport_size.width());
   const float content_width_css = metadata.root_layer_size.width();
   if (content_width_css <= window_width_dip)
     view_flags |= InputRouter::MOBILE_VIEWPORT;
 
   return view_flags;
 }
 
 // Implements the RenderWidgetHostIterator interface. It keeps a list of
 // RenderWidgetHosts, and makes sure it returns a live RenderWidgetHost at each
 // iteration (or NULL if there isn't any left).
@@ skipping 2258 matching lines @@
   }
 }
 
 SkColorType RenderWidgetHostImpl::PreferredReadbackFormat() {
   if (view_)
     return view_->PreferredReadbackFormat();
   return kN32_SkColorType;
 }
 
 }  // namespace content