Begin implementing V8 bindings for Mojo

This CL contains the beginnings of JavaScript bindings for the core Mojo
system. The approach in this CL is to bind as close to the "metal" as possible
so as to self-host as much as possiblem in the VM. I've tried to avoid
retaining any state on the C++ side of the bindings, but I didn't quite succeed
because V8 requires embedders to retain state in order to access the memory
that backs ArrayBuffers.

In this CL, I've added some basic bindings for the symbols exported by core.h.
Specifically, I've created bindings for CreateMessagePipe, Close, Wait,
WaitMany, WriteMessage, and ReadMessage.

R=aa@chromium.org, darin@chromium.org
BUG=317398

Review URL: https://codereview.chromium.org/59153005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234347 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234347
[NaCl SDK] AppEngine: Update all demos to have FPS counter

BUG=none
R=nfullagar@chromium.org, sbc@chromium.org

Review URL: https://codereview.chromium.org/59023005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234348 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234348