Use a mocked compositor for unit tests

chrome/test/base/chrome_test_suite.cc

Index: chrome/test/base/chrome_test_suite.cc
diff --git a/chrome/test/base/chrome_test_suite.cc b/chrome/test/base/chrome_test_suite.cc
index fa02aa99ee185727bf3d304d00d2f64b66c6320d..0a3d50b24145a20cc7b4768be0077521d4d9811b 100644
--- a/chrome/test/base/chrome_test_suite.cc
+++ b/chrome/test/base/chrome_test_suite.cc
@@ -196,11 +196,6 @@ void ChromeTestSuite::Initialize() {
       resources_pack_path.Append(FILE_PATH_LITERAL("resources.pak"));
   ResourceBundle::AddDataPackToSharedInstance(resources_pack_path);
 
-#if defined(TOOLKIT_VIEWS) && defined(OS_LINUX)
-  // Turn of GPU compositing in browser during unit tests.
-  views::View::set_use_acceleration_when_possible(false);
-#endif
-
   stats_filename_ = base::StringPrintf("unit_tests-%d",
                                        base::GetCurrentProcId());
   RemoveSharedMemoryFile(stats_filename_);