Bug 977359 Part 1: Fix ImageBridgeChild deadlock in the Nuwa process by freezing the thread after the actor is opened. r=gal,nical,khuey
Bug 977359 Part 2: Test case for the deadlock in the Nuwa process. r=gal
Bug 977359 Part 3: Remove runtime checks for Nuwa deadlock in debug build. r=khuey