Perform direct routing of mouse events when the pointer is locked.

content/browser/renderer_host/render_widget_host_delegate.h

Index: content/browser/renderer_host/render_widget_host_delegate.h
diff --git a/content/browser/renderer_host/render_widget_host_delegate.h b/content/browser/renderer_host/render_widget_host_delegate.h
index 79efc0ff2a52aec1b35575b3c57998cb047abac1..32bb92d42a85ec2eea448bf54251c3a90b168f34 100644
--- a/content/browser/renderer_host/render_widget_host_delegate.h
+++ b/content/browser/renderer_host/render_widget_host_delegate.h
@@ -184,6 +184,10 @@ class CONTENT_EXPORT RenderWidgetHostDelegate {
   // Returns true if |render_widget_host| holds the mouse lock.
   virtual bool HasMouseLock(RenderWidgetHostImpl* render_widget_host);
 
+  // Returns the widget that holds the mouse lock or nullptr if the mouse isn't
+  // locked.
+  virtual RenderWidgetHostImpl* GetMouseLockWidget();
+
   // Called when the visibility of the RenderFrameProxyHost in outer
   // WebContents changes. This method is only called on an inner WebContents and
   // will eventually notify all the RenderWidgetHostViews belonging to that