Added a command line switch kRenderClientId. It holds the process ID of a browser process and is passed to a renderer process when the render process is created. RenderWidget stores the client ID into its client_id_ field and use it to construct a FrameSinkID when RenderWidgetCompositor is created in RenderWidget::InitializeLayerTreeView.
This change should fix a bug where SurfaceSequence::frame_sink_id is empty in SurfaceLayer::SatisfyDestroySequence().
BUG=
656639
Committed:
https://crrev.com/067f5824a3d561b9a16774fed995c23b6854405f
Cr-Commit-Position: refs/heads/master@{#430375}