Implement pointer lock API for out-of-process iframes.

content/browser/frame_host/render_widget_host_view_child_frame.cc

Index: content/browser/frame_host/render_widget_host_view_child_frame.cc
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame.cc b/content/browser/frame_host/render_widget_host_view_child_frame.cc
index 7101a901d12d64c5f8367a5d904cb73520fbd593..c481a8dfc66c0a05fd1f0772aa1dae1378d0ad24 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame.cc
+++ b/content/browser/frame_host/render_widget_host_view_child_frame.cc
@@ -477,12 +477,26 @@ void RenderWidgetHostViewChildFrame::ProcessAckedTouchEvent(
 }
 
 bool RenderWidgetHostViewChildFrame::LockMouse() {
+  if (frame_connector_)
+    return frame_connector_->LockMouse();
   return false;
 }
 
 void RenderWidgetHostViewChildFrame::UnlockMouse() {
 }
 
+bool RenderWidgetHostViewChildFrame::IsMouseLocked() {
+  if (frame_connector_) {

[nasko, 2016/05/25 21:12:01]

Why not early return false if !frame_connector_? It removes a level of
indentation.

[lfg, 2016/05/31 21:13:20]

In this case I need two 'return false' since the root_view may be null (though
root_view can only be null in tests).

+    RenderWidgetHostViewBase* root_view =
+        frame_connector_->GetRootRenderWidgetHostView();
+
+    if (root_view)
+      return root_view->IsMouseLocked();
+  }
+
+  return false;
+}
+
 uint32_t RenderWidgetHostViewChildFrame::GetSurfaceIdNamespace() {
   return id_allocator_->id_namespace();
 }