Use stub GL draw/clear calls for browser tests that do not need pixels.

content/public/test/browser_test_base.h

Index: content/public/test/browser_test_base.h
diff --git a/content/public/test/browser_test_base.h b/content/public/test/browser_test_base.h
index 901f34368ef46d84122829ed755fc5fb1b36f482..724c61d918ad0ca341972bff26171a60dea02125 100644
--- a/content/public/test/browser_test_base.h
+++ b/content/public/test/browser_test_base.h
@@ -122,10 +122,6 @@ class BrowserTestBase : public testing::Test {
   // test.
   void UseRealGLContexts();
 
-  // Call this before SetUp() to use real GL drivers instead of OSMesa for the
-  // test.
-  void UseRealGLBindings();
-
   // Call this before SetUp() to not use GL, but use software compositing
   // instead.
   void UseSoftwareCompositing();
@@ -149,10 +145,6 @@ class BrowserTestBase : public testing::Test {
   // the test, so that it produces real pixel output.
   bool allow_test_contexts_;
 
-  // When false, the GL backend will use a real GPU. When true, it uses OSMesa
-  // to run GL on the CPU in a way that works across all platforms.
-  bool allow_osmesa_;
-
   // When true, do compositing with the software backend instead of using GL.
   bool use_software_compositing_;