[SyncFS] Implement base case of RemoteToLocalSyncer::HandleDelete.

BUG=240165
NOTRY=true

Review URL: https://codereview.chromium.org/61633002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233604 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233604
WebSocketBasicStream should ignore empty buffer

If an empty read buffer is passed to the WebSocketBasicStream
constructor, it should disregard it. Make it so.

Review URL: https://codereview.chromium.org/63573003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233605 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233605