Revert of cc: Use worker context for one-copy tile initialization.

cc/output/context_provider.h

Index: cc/output/context_provider.h
diff --git a/cc/output/context_provider.h b/cc/output/context_provider.h
index c024e02328e9a3930b7593e54b986bdff3566ae5..aa4367d97ff68d515b22121b7cb89b25fba4ad57 100644
--- a/cc/output/context_provider.h
+++ b/cc/output/context_provider.h
@@ -7,7 +7,6 @@
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
-#include "base/synchronization/lock.h"
 #include "cc/base/cc_export.h"
 #include "gpu/command_buffer/common/capabilities.h"
 
@@ -27,27 +26,6 @@
 
 class ContextProvider : public base::RefCountedThreadSafe<ContextProvider> {
  public:
-  class ScopedContextLock {
-   public:
-    explicit ScopedContextLock(ContextProvider* context_provider)
-        : context_provider_(context_provider),
-          context_lock_(*context_provider_->GetLock()) {
-      // Allow current thread to bind to |context_provider|.
-      context_provider_->DetachFromThread();
-    }
-    ~ScopedContextLock() {
-      // Allow a different thread to bind to |context_provider|.
-      context_provider_->DetachFromThread();
-    }
-
-    gpu::gles2::GLES2Interface* ContextGL() {
-      return context_provider_->ContextGL();
-    }
-
-   private:
-    ContextProvider* const context_provider_;
-    base::AutoLock context_lock_;
-  };
   // Bind the 3d context to the current thread. This should be called before
   // accessing the contexts. Calling it more than once should have no effect.
   // Once this function has been called, the class should only be accessed