GTTF: Extract ResultsPrinter out of test_launcher.

This will be helpful as it'll grow when I add infrastructure
to produce a JSON file for the entire test run (all iterations).

BUG=236893
R=sky@chromium.org

Review URL: https://codereview.chromium.org/26294005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227536 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227536
Destroy references to context3d_ before leaking it and setting to NULL.

The ContextProviderCommandBuffer callback proxies make use of the
provider's context3d_ when they are destroyed. If the context is to
be leaked on shutdown however, we leak the context3d_ and set it
to NULL in the destructor. Then the callback proxies will try to use
a NULL pointer. So, destroy them before leaking the context3d_.

Tests:
ContextProviderCommandBufferBrowserTest.LeakOnDestroy

R=piman
BUG=304861

Review URL: https://codereview.chromium.org/26182004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227537 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227537