Convert over to channel handles

This hides some of the internals of the posix channels from users, and gets rid
of several #ifdef POSIX blocks. Generally simplifies usage of channels xplatform.

BUG=none
TEST=build

Review URL: http://codereview.chromium.org/5598010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68621 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ppapi/proxy/dispatcher.cc b/ppapi/proxy/dispatcher.cc
index 072134d2..3f18877 100644
--- a/ppapi/proxy/dispatcher.cc
+++ b/ppapi/proxy/dispatcher.cc
@@ -77,12 +77,12 @@
 }
 
 bool Dispatcher::InitWithChannel(MessageLoop* ipc_message_loop,
-                                 const std::string& channel_name,
+                                 const IPC::ChannelHandle& channel_handle,
                                  bool is_client,
                                  base::WaitableEvent* shutdown_event) {
   IPC::Channel::Mode mode = is_client ? IPC::Channel::MODE_CLIENT
                                       : IPC::Channel::MODE_SERVER;
-  channel_.reset(new IPC::SyncChannel(channel_name, mode, this,
+  channel_.reset(new IPC::SyncChannel(channel_handle, mode, this,
                                       ipc_message_loop, false, shutdown_event));
   return true;
 }