[Chromoting] The desktop process now creates a pre-connected pipe and passes (with some help of the daemon) its client-end handle to the network process. The network process will request screen/audio capturing and input injection services using the created channel.

Accompanying changes:
- The daemon can request other processes to crash in response to critical protocol errors.
- Both network and desktop processes exit if the connection to the daemon has been disconnected.
- CreateConnectedIpcChannel() function moved to remoting/host/win/launch_process_with_token.h
- IPC::Channel::GenerateUniqueRandomChannelID() is used to generate a unique channel name.
- Added unit tests for DesktopProcess.
- Made 'remote_desktop' compilable on all platforms.

BUG=134694

Review URL: https://chromiumcodereview.appspot.com/11231060

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@164006 0039d316-1c4b-4281-b951-d872f2087c98