Pepper: Use shared memory for ArrayBufferVar.

This change improves performance for sending ArrayBufferVars between the
plugin and the host. It copies the data from the var into a shared
memory region and sends the shared memory handle over IPC.

This required defining a new message for plugins to request the host to
create shared memory.

BUG=


Review URL: https://chromiumcodereview.appspot.com/11827059

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@189089 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ppapi/ppapi_proxy.gypi b/ppapi/ppapi_proxy.gypi
index 9978a42..838bbc6 100644
--- a/ppapi/ppapi_proxy.gypi
+++ b/ppapi/ppapi_proxy.gypi
@@ -88,6 +88,7 @@
           'proxy/plugin_var_tracker.h',
           'proxy/ppapi_command_buffer_proxy.h',
           'proxy/ppapi_command_buffer_proxy.cc',
+          'proxy/ppapi_messages.h',
           'proxy/ppapi_message_utils.h',
           'proxy/ppb_audio_proxy.cc',
           'proxy/ppb_audio_proxy.h',