GitLab

- RemoveEntryFromDirectory() was a misnomer. It removes an entry if it's
  not on the root directory. The |dir_path| parameter was unnecessary
  as it can be obtained from |file_path|.
  New name: RemoveEntryFromNonRootDirectory()

- RemoveEntryFromDirectoryOnFileSystem() was a misnomer. It moves an
  entry to the root directory on the client side
  New name: MoveEntryToRootDirectoryOnClientSide()

- Rename *OnFileSystem() with *OnClientSide() to make it clear these are
  client side operations

- Rename OnMoveEntryToDirectoryWithFileMoveCallback() to
  NotifyAndRunFileMoveCallback() based on what it does

- Rename OnMoveEntryToDirectoryWithFileOperationCallback() to
  NotifyAndRunFileOperationCallback() based on what it does

Along the way, eliminate if (!callback.is_null()) and PostTask() from
places where these are unnecessary.

BUG=126634, 139446
TEST=moving and renaming of files on Drive works as before

Review URL: https://chromiumcodereview.appspot.com/10832233

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151115 0039d316-1c4b-4281-b951-d872f2087c98