Revert 227492 "Moved all channel-handling logic into separate Na..."

Seems causing remoting_unittests failure on "Linux ASAN Tests"
http://build.chromium.org/p/chromium.memory/builders/Linux%20ASAN%20Tests%20%282%29/builds/18265
> Moved all channel-handling logic into separate NativeMessagingChannel class.
> 
> Changes in this CL:
>  - NativeMessagingHost is used only for actual processing the messages.
>  - NativeMessagingChannel implements receiving and sending messages.
>  - NativeMessagingChannel takes ownership of the passed inout and output handles.
>  - Both NativeMessagingChannel and NativeMessagingHost are explicitly marked as not thread-safe classes.
> 
> BUG=173509
> 
> Review URL: https://codereview.chromium.org/23903021

TBR=alexeypa@chromium.org

Review URL: https://codereview.chromium.org/26471003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227497 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227497