Made Blink aware of top controls offset (Chromium-side)

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 797d2d138fffa548cba3f8a8433c17d306324911..328234f5fd100d7fcbcf595ed3f1f3434919c81c 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -92,7 +92,11 @@ LayerTreeImpl::LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl)
       needs_full_tree_sync_(true),
       next_activation_forces_redraw_(false),
       has_ever_been_drawn_(false),
-      render_surface_layer_list_id_(0) {
+      render_surface_layer_list_id_(0),
+      top_controls_layout_height_(0),
+      top_controls_top_offset_(0),
+      top_controls_delta_(0),
+      sent_top_controls_delta_(0) {
 }
 
 LayerTreeImpl::~LayerTreeImpl() {
@@ -200,6 +204,13 @@ void LayerTreeImpl::PushPropertiesTo(LayerTreeImpl* target_tree) {
 
   target_tree->PassSwapPromises(&swap_promise_list_);
 
+  target_tree->top_controls_layout_height_ = top_controls_layout_height_;
+  target_tree->top_controls_top_offset_ = top_controls_top_offset_;
+  target_tree->top_controls_delta_ =
+      target_tree->top_controls_delta_ -
+          target_tree->sent_top_controls_delta_;
+  target_tree->sent_top_controls_delta_ = 0.f;
+
   target_tree->SetPageScaleValues(
       page_scale_factor(), min_page_scale_factor(), max_page_scale_factor(),
       target_tree->page_scale_delta() / target_tree->sent_page_scale_delta());
@@ -376,6 +387,10 @@ void LayerTreeImpl::ApplySentScrollAndScaleDeltasFromAbortedCommit() {
   page_scale_delta_ /= sent_page_scale_delta_;
   sent_page_scale_delta_ = 1.f;
 
+  top_controls_top_offset_ += sent_top_controls_delta_;
+  top_controls_delta_ -= sent_top_controls_delta_;
+  sent_top_controls_delta_ = 0.f;
+
   if (!root_layer())
     return;