Allows fullscreen to be triggered with the key events used for scrolling.

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index 4e14b11d68cc7a1f7c36a6c7f0eae7345d080c6b..a0c835a333450fdc3f4c96b0b1c894361e8e7aa5 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -237,6 +237,7 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
   void UpdateTopControlsState(TopControlsState constraints,
                               TopControlsState current,
                               bool animate);
+  void UpdateTopControlsStatePreservingConstraints(bool show);
 
   HeadsUpDisplayLayer* hud_layer() const { return hud_layer_.get(); }
 
@@ -255,6 +256,7 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
 
   bool in_paint_layer_contents() const { return in_paint_layer_contents_; }
 
+
   void IncrementLCDTextMetrics(
       bool update_total_num_cc_layers_can_use_lcd_text,
       bool update_total_num_cc_layers_will_use_lcd_text);