Pass allow_delayed_resize in CompositorFrameMetadata

cc/output/compositor_frame_metadata.h

 // 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.
 
 #ifndef CC_OUTPUT_COMPOSITOR_FRAME_METADATA_H_
 #define CC_OUTPUT_COMPOSITOR_FRAME_METADATA_H_
 
 #include <vector>
 
 #include "cc/base/cc_export.h"
@@ skipping 22 matching lines @@
   gfx::SizeF root_layer_size;
   float min_page_scale_factor;
   float max_page_scale_factor;
 
   // Used to position the Android location top bar and page content, whose
   // precise position is computed by the renderer compositor.
   gfx::Vector2dF location_bar_offset;
   gfx::Vector2dF location_bar_content_translation;
   float overdraw_bottom_height;
 
+  // When showing or hiding top controls, the compositor calculates
+  // |viewport_size| according to the original viewport size and the position
+  // of the top controls. However, the viewport size of blink is only updated
+  // after the browser sends the resize event, causing inconsistency between
+  // the compositor and blink about the position of bottom-fixed-position
+  // elements. When such elements exist, the browser needs to send the resize
+  // event before sending any position-related events; otherwise it can delay
+  // the event if needed.
+  bool allow_delayed_resize;
+
   std::vector<ui::LatencyInfo> latency_info;
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_COMPOSITOR_FRAME_METADATA_H_