Fix main thread top controls scrolling to mirror CC.

content/renderer/render_widget.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/renderer/render_widget.h"
 
 #include <utility>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 1118 matching lines @@
   top_controls_height_ = params.top_controls_height;
   visible_viewport_size_ = params.visible_viewport_size;
   resizer_rect_ = params.resizer_rect;
 
   // NOTE: We may have entered fullscreen mode without changing our size.
   bool fullscreen_change =
       is_fullscreen_granted_ != params.is_fullscreen_granted;
   is_fullscreen_granted_ = params.is_fullscreen_granted;
   display_mode_ = params.display_mode;
 
-  webwidget_->setTopControlsHeight(params.top_controls_height,
-                                   top_controls_shrink_blink_size_);
-
   if (resized) {
     gfx::Size new_widget_size = size_;
     if (IsUseZoomForDSFEnabled()) {
       new_widget_size = gfx::ScaleToCeiledSize(new_widget_size,
                                                GetOriginalDeviceScaleFactor());
     }
     // When resizing, we want to wait to paint before ACK'ing the resize.  This
     // ensures that we only resize as fast as we can paint.  We only need to
     // send an ACK if we are resized to a non-empty rect.
-    webwidget_->resize(new_widget_size);
+    webwidget_->resize(
+        new_widget_size,
+        top_controls_height_,
+        top_controls_shrink_blink_size_);

[majidvp, 2016/04/06 18:07:30]

I think for the top control anchoring to work correctly
you also need to resize the visual viewport in the same call.
This mean folding WebWidget::resizeVisualViewport into
the same same resize call.

[bokan, 2016/04/06 19:23:35]

We already do this in WebViewImpl::performResize. When resize is called, both
viewports are resized. The call below to resizeVisualViewport is for the OSK
where we might not have a layout affecting resize (i.e. resized == false above).

   }
   WebSize visual_viewport_size;
 
   if (IsUseZoomForDSFEnabled()) {
     visual_viewport_size = gfx::ScaleToCeiledSize(
         params.visible_viewport_size,
         GetOriginalDeviceScaleFactor());
   } else {
     visual_viewport_size = visible_viewport_size_;
   }
@@ skipping 986 matching lines @@
 }
 
 float RenderWidget::GetOriginalDeviceScaleFactor() const {
   return
       screen_metrics_emulator_ ?
       screen_metrics_emulator_->original_screen_info().deviceScaleFactor :
       device_scale_factor_;
 }
 
 }  // namespace content