Support screen.lockOrientation() / screen.unlockOrientation() when running layout tests

content/public/test/layouttest_support.h

Index: content/public/test/layouttest_support.h
diff --git a/content/public/test/layouttest_support.h b/content/public/test/layouttest_support.h
index b935765be0b00301bd1b21d21795439d568f3df3..e28df6be65cbc514d5fa0429d8546ae7bdb7e42a 100644
--- a/content/public/test/layouttest_support.h
+++ b/content/public/test/layouttest_support.h
@@ -63,6 +63,9 @@ void SetMockDeviceOrientationData(const blink::WebDeviceOrientationData& data);
 void SetMockScreenOrientation(
     const blink::WebScreenOrientationType& orientation);
 
+// Resets the mock screen orientation data.
+void ResetMockScreenOrientation();
+
 // Returns the length of the local session history of a render view.
 int GetLocalSessionHistoryLength(RenderView* render_view);