ui: Allow individual test suites to opt-out of the TestCompositor.

ui/compositor/test/context_factories_for_test.cc

Index: ui/compositor/test/context_factories_for_test.cc
diff --git a/ui/compositor/test/context_factories_for_test.cc b/ui/compositor/test/context_factories_for_test.cc
index 0c452c529e4b2ff56f257b3cfd209530a953557c..63b2d3a2c74099d778ecb8f6cbe82835f717e125 100644
--- a/ui/compositor/test/context_factories_for_test.cc
+++ b/ui/compositor/test/context_factories_for_test.cc
@@ -12,19 +12,29 @@
 #include "ui/compositor/test/test_context_factory.h"
 #include "ui/gl/gl_implementation.h"
 
-namespace ui {
+namespace {
+
+static ui::ContextFactory* g_implicit_factory = NULL;
+static gfx::DisableNullDrawGLBindings* g_disable_null_draw = NULL;
 
-static ContextFactory* g_implicit_factory = NULL;
+}  // namespace
+
+namespace ui {
 
 // static
 void InitializeContextFactoryForTests(bool enable_pixel_output) {
   DCHECK(!g_implicit_factory) <<
       "ContextFactory for tests already initialized.";
+  CommandLine* command_line = CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kEnablePixelOutputInTests))
+    enable_pixel_output = true;
 
   bool use_test_contexts = true;
 
+  if (gfx::HasInitializedNullDrawGLBindings())
+    use_test_contexts = false;
+
   // Always use test contexts unless the disable command line flag is used.
-  CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kDisableTestCompositor))
     use_test_contexts = false;
 
@@ -43,6 +53,8 @@ void InitializeContextFactoryForTests(bool enable_pixel_output) {
   } else {
     DCHECK_NE(gfx::kGLImplementationNone, gfx::GetGLImplementation());
     DVLOG(1) << "Using InProcessContextFactory";
+    if (enable_pixel_output && gfx::HasInitializedNullDrawGLBindings())
+      g_disable_null_draw = new gfx::DisableNullDrawGLBindings;
     g_implicit_factory = new ui::InProcessContextFactory();
   }
   ContextFactory::SetInstance(g_implicit_factory);
@@ -52,6 +64,8 @@ void TerminateContextFactoryForTests() {
   ContextFactory::SetInstance(NULL);
   delete g_implicit_factory;
   g_implicit_factory = NULL;
+  delete g_disable_null_draw;
+  g_disable_null_draw = NULL;
 }
 
 }  // namespace ui