Decouple cc::FakeWebGraphicsContext3D from blink::WGC3D

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index 5f443eefa531a48cecaaa34e07acde27de178392..896028d9445568671400407e689a30930f211bfc 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -166,7 +166,6 @@ GLRenderer::GLRenderer(RendererClient* client,
     : DirectRenderer(client, settings, output_surface, resource_provider),
       offscreen_framebuffer_id_(0),
       shared_geometry_quad_(gfx::RectF(-0.5f, -0.5f, 1.0f, 1.0f)),
-      context_(output_surface->context_provider()->Context3d()),
       gl_(output_surface->context_provider()->ContextGL()),
       context_support_(output_surface->context_provider()->ContextSupport()),
       texture_mailbox_deleter_(texture_mailbox_deleter),
@@ -226,8 +225,6 @@ const RendererCapabilities& GLRenderer::Capabilities() const {
   return capabilities_;
 }
 
-WebGraphicsContext3D* GLRenderer::Context() { return context_; }
-
 void GLRenderer::DebugGLCall(GLES2Interface* gl,
                              const char* command,
                              const char* file,