Fix main thread top controls scrolling to mirror CC.

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 0f53306133004e870e0fbca12970d1156fdd0860..011448fdbbf304fdc69215608a1622f49981e323 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -218,8 +218,6 @@ RenderWidget::RenderWidget(CompositorDependencies* compositor_deps,
       webwidget_(nullptr),
       owner_delegate_(nullptr),
       opener_id_(MSG_ROUTING_NONE),
-      top_controls_shrink_blink_size_(false),
-      top_controls_height_(0.f),
       next_paint_flags_(0),
       auto_resize_mode_(false),
       need_update_rect_for_auto_resize_(false),
@@ -515,8 +513,6 @@ void RenderWidget::SetWindowRectSynchronously(
   params.new_size = new_window_rect.size();
   params.physical_backing_size =
       gfx::ScaleToCeiledSize(new_window_rect.size(), device_scale_factor_);
-  params.top_controls_shrink_blink_size = top_controls_shrink_blink_size_;
-  params.top_controls_height = top_controls_height_;
   params.visible_viewport_size = new_window_rect.size();
   params.resizer_rect = gfx::Rect();
   params.is_fullscreen_granted = is_fullscreen_granted_;
@@ -584,9 +580,6 @@ void RenderWidget::OnEnableDeviceEmulation(
     resize_params.new_size = size_;
     resize_params.physical_backing_size = physical_backing_size_;
     resize_params.visible_viewport_size = visible_viewport_size_;
-    resize_params.top_controls_shrink_blink_size =
-        top_controls_shrink_blink_size_;
-    resize_params.top_controls_height = top_controls_height_;
     resize_params.resizer_rect = resizer_rect_;
     resize_params.is_fullscreen_granted = is_fullscreen_granted_;
     resize_params.display_mode = display_mode_;
@@ -1098,6 +1091,11 @@ void RenderWidget::Redraw() {
     compositor_->SetNeedsRedrawRect(gfx::Rect(size_));
 }
 
+void RenderWidget::ResizeWebWidget(const gfx::Size& new_size, bool resized) {
+    if (resized)

[no sievers, 2016/04/12 22:44:12]

Hmm, weird pattern with passing a bool to a function that tells it to not
perform the function. Can you leave that check with the caller?

[bokan, 2016/04/13 17:25:39]

Agree that its odd but I'm not sure there's a clean way without doing some
rearranging. The reason I put it there is because if only the top controls
height changes, we still want to call resize in RenderView's version.
Unfortunately, RenderWidget can't check the current top control height.

I made ResizeWebWidget take the ResizeParams and make it set the various private
vars like size_ and physical_backing_size_. That way it can calculate whether a
resize occurred itself and the RenderView version can also check for a change in
top_controls_height_. I uploaded a new CL that does this. It's not ideal IMO
since there's quite a bit of duplication. The other alternative is to make more
virtual methods that RenderView overrides but then we'd need bool
NeedsWebWidgetResize(ResizeParams), void StoreResizeParams(ResizeParams),
ResizeWebWidget(ResizeParams) which seems like overkill.

Ideally, we could get rid of the resized check altogether and rely on WebWidget
implementations not to do anything unless something's changed. It seems just
plugins and popups are missing an early out right now, maybe it'd make sense to
add that there in a pre/post patch? Let me know your preference.

+        webwidget_->resize(new_size);
+}
+
 void RenderWidget::Resize(const ResizeParams& params) {
   bool orientation_changed =
       screen_info_.orientationAngle != params.screen_info.orientationAngle ||
@@ -1125,8 +1123,6 @@ void RenderWidget::Resize(const ResizeParams& params) {
   size_ = params.new_size;
   physical_backing_size_ = params.physical_backing_size;
 
-  top_controls_shrink_blink_size_ = params.top_controls_shrink_blink_size;
-  top_controls_height_ = params.top_controls_height;
   visible_viewport_size_ = params.visible_viewport_size;
   resizer_rect_ = params.resizer_rect;
 
@@ -1136,20 +1132,16 @@ void RenderWidget::Resize(const ResizeParams& params) {
   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);
+  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.
+  ResizeWebWidget(new_widget_size, resized);
+
   WebSize visual_viewport_size;
 
   if (IsUseZoomForDSFEnabled()) {