cc: Use the correct internal format for glCopyTexImage2D calls.

cc/test/test_in_process_context_provider.cc

Index: cc/test/test_in_process_context_provider.cc
diff --git a/cc/test/test_in_process_context_provider.cc b/cc/test/test_in_process_context_provider.cc
index 51d43023c4ce0339f8d5b4b3917d2fb5bbf3a576..43f8196156ed448689c7edc31da319f76248d5b2 100644
--- a/cc/test/test_in_process_context_provider.cc
+++ b/cc/test/test_in_process_context_provider.cc
@@ -32,10 +32,7 @@ std::unique_ptr<gpu::GLInProcessContext> CreateTestInProcessContext(
     gpu::GLInProcessContext* shared_context) {
   const bool is_offscreen = true;
   gpu::gles2::ContextCreationAttribHelper attribs;
-  attribs.alpha_size = 8;
-  attribs.blue_size = 8;
-  attribs.green_size = 8;
-  attribs.red_size = 8;
+  attribs.alpha_size = -1;
   attribs.depth_size = 24;
   attribs.stencil_size = 8;
   attribs.samples = 0;