Make MockScreenOrientationClient an internal detail of components/test_runner.

components/test_runner/web_test_proxy.cc

Index: components/test_runner/web_test_proxy.cc
diff --git a/components/test_runner/web_test_proxy.cc b/components/test_runner/web_test_proxy.cc
index 2db9db404915ba7294af2f13e4c9b7e383f282fd..0f181e584eaca7b7399dc1366d10aa363a1226ba 100644
--- a/components/test_runner/web_test_proxy.cc
+++ b/components/test_runner/web_test_proxy.cc
@@ -608,21 +608,17 @@ void WebTestProxyBase::LayoutAndPaintAsyncThen(const base::Closure& callback) {
 
 void WebTestProxyBase::GetScreenOrientationForTesting(
     blink::WebScreenInfo& screen_info) {
-  if (!screen_orientation_client_ || screen_orientation_client_->IsDisabled())
+  MockScreenOrientationClient* mock_client = GetScreenOrientationClientMock();
+  if (mock_client->IsDisabled())

[Łukasz Anforowicz, 2016/03/16 00:16:01]

This is a slightly different condition than before (because now mock_client is
always non-null), but
1) Previously the existance, non-nullness of screen_orientation_client_
   would depend on previous occurence of WebFrameClient (or WebFrameTestProxy)
   webScreenOrientationClient method.  This seems more fragile, than only
   depending on flags directly calls by tests (i.e. tests can disable by
   calling testRunner.disableMockScreenOrientation() from javascript).
2) Tests pass on the trybots.

     return;
   // Override screen orientation information with mock data.
-  screen_info.orientationType =
-      screen_orientation_client_->CurrentOrientationType();
-  screen_info.orientationAngle =
-      screen_orientation_client_->CurrentOrientationAngle();
+  screen_info.orientationType = mock_client->CurrentOrientationType();
+  screen_info.orientationAngle = mock_client->CurrentOrientationAngle();
 }
 
 MockScreenOrientationClient*
 WebTestProxyBase::GetScreenOrientationClientMock() {
-  if (!screen_orientation_client_.get()) {
-    screen_orientation_client_.reset(new MockScreenOrientationClient);
-  }
-  return screen_orientation_client_.get();
+  return test_interfaces_->GetTestRunner()->getMockScreenOrientationClient();
 }
 
 MockWebSpeechRecognizer* WebTestProxyBase::GetSpeechRecognizerMock() {