Move code in ui/gl/* from gfx:: to gl::

gpu/command_buffer/service/mailbox_manager_unittest.cc

Index: gpu/command_buffer/service/mailbox_manager_unittest.cc
diff --git a/gpu/command_buffer/service/mailbox_manager_unittest.cc b/gpu/command_buffer/service/mailbox_manager_unittest.cc
index 735fd4a151250f8814628b5221e078ff82a37bee..0c2a1e0f1e54dad240c81c09fe0857582738bf71 100644
--- a/gpu/command_buffer/service/mailbox_manager_unittest.cc
+++ b/gpu/command_buffer/service/mailbox_manager_unittest.cc
@@ -198,8 +198,8 @@ class MailboxManagerSyncTest : public MailboxManagerTest {
   void SetUp() override {
     MailboxManagerTest::SetUpWithSynchronizer();
     manager2_ = new MailboxManagerSync();
-    context_ = new gfx::GLContextStub();
-    surface_ = new gfx::GLSurfaceStub();
+    context_ = new gl::GLContextStub();
+    surface_ = new gl::GLSurfaceStub();
     context_->MakeCurrent(surface_.get());
   }
 
@@ -253,8 +253,8 @@ class MailboxManagerSyncTest : public MailboxManagerTest {
   }
 
   scoped_refptr<MailboxManager> manager2_;
-  scoped_refptr<gfx::GLContext> context_;
-  scoped_refptr<gfx::GLSurface> surface_;
+  scoped_refptr<gl::GLContext> context_;
+  scoped_refptr<gl::GLSurface> surface_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MailboxManagerSyncTest);