aura: Clean up compositor initialization/destruction.

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 26f7c0700205871ac5cc29acbdf011ab945ad854..521ba76955c4829f0f17834a14c7222de6134e52 100644
--- a/content/public/test/browser_test_base.h
+++ b/content/public/test/browser_test_base.h
@@ -109,6 +109,9 @@ class BrowserTestBase : public testing::Test {
   // returns.
   void PostTaskToInProcessRendererAndWait(const base::Closure& task);
 
+  // Call this in SetUp() to use real GL contexts in Compositor for the test.
+  void DoNotUseTestContexts() { allow_test_contexts_ = false; }
+
  private:
   void ProxyRunTestOnMainThreadLoop();
 
@@ -118,6 +121,10 @@ class BrowserTestBase : public testing::Test {
   // Embedded test server, cheap to create, started on demand.
   scoped_ptr<net::test_server::EmbeddedTestServer> embedded_test_server_;
 
+  // When false, the ui::Compositor will be forced to use real GL contexts for
+  // the test, so that it produces real pixel output.
+  bool allow_test_contexts_;
+
 #if defined(OS_POSIX)
   bool handle_sigterm_;
 #endif