cc: Implement shared worker contexts. (v1)

mojo/cc/context_provider_mojo.h

Index: mojo/cc/context_provider_mojo.h
diff --git a/mojo/cc/context_provider_mojo.h b/mojo/cc/context_provider_mojo.h
index cc465d06837aed9675186a170cec67500d1a97f4..1eaa6a5803309f232c7db3bd30356736252d7347 100644
--- a/mojo/cc/context_provider_mojo.h
+++ b/mojo/cc/context_provider_mojo.h
@@ -29,12 +29,13 @@ class ContextProviderMojo : public cc::ContextProvider {
   Capabilities ContextCapabilities() override;
   void VerifyContexts() override {}
   void DeleteCachedResources() override {}
-  bool DestroyedOnMainThread() override;
+  bool HasBeenLostOnMainThread() override;
   void SetLostContextCallback(
       const LostContextCallback& lost_context_callback) override {}
   void SetMemoryPolicyChangedCallback(
       const MemoryPolicyChangedCallback& memory_policy_changed_callback)
       override {}
+  bool HasBeenDestroyed() override;
 
  protected:
   friend class base::RefCountedThreadSafe<ContextProviderMojo>;