GitLab

Use the RenderWidgetResizeHelper's task runner to handle the mojo
messages to and from the BridgedNativeWidget and
BridgedNativeWidgetHost.

Bug: 859152
Change-Id: I3d9fab6cd81edafd74e45d06c658d1bd15e1fde4
Reviewed-on: https://chromium-review.googlesource.com/1244103
Commit-Queue: Sidney San Martín <sdy@chromium.org>
Reviewed-by: Sidney San Martín <sdy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594134}