Only create compositor thread context once.

The RenderWidgetCompositor asks the SharedContext3D to create
its compositor thread context every frame. This causes us to
destroy the old (valid) context, which tears down the
CommandBufferProxyImpl on the main thread causing an assertion.

We should only create a new context the first time we create the
ContextProvider, ie only on first use and after a context loss.
This change keeps the existing code from asserting, though the
code will be replaced entirely soon by moving context ownership
and the ContextProvider to RenderThreadImpl.

R=jamesr,piman
BUG=177768


Review URL: https://chromiumcodereview.appspot.com/12340076

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@184736 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed