NaCl: Add tests to check that some IRT interfaces are disabled under PNaCl

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3803
TEST=browser_tests
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/190823004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255721 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255721
Revert 255481 "Remove --ui-prioritize-in-gpu-process"

Reverting to see whether this introduced flakiness in the WebGL conformance
tests on the Win GPU bots. If it did, that means this CL exposed a
preexisting race condition. See Issue 350572.

> Remove --ui-prioritize-in-gpu-process
> 
> It is already always on on Android and Chrome OS. Consensus is that we should
> turn on on all Aura platform. The flag is a noop on other platforms.
> 
> BUG=344083
> 
> Review URL: https://codereview.chromium.org/183883023

TBR=piman@chromium.org
BUG=344083,350572

Review URL: https://codereview.chromium.org/189373012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255722 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255722