Remove now-unnecessary wrappers around gfx::Screen::GetScreen()

extensions/browser/api/system_display/display_info_provider.h

Index: extensions/browser/api/system_display/display_info_provider.h
diff --git a/extensions/browser/api/system_display/display_info_provider.h b/extensions/browser/api/system_display/display_info_provider.h
index e2fee24303d7015c4e55b162d22ab82b6d5203d8..15d719f80218a4ffe24ff3185033b6037a023703 100644
--- a/extensions/browser/api/system_display/display_info_provider.h
+++ b/extensions/browser/api/system_display/display_info_provider.h
@@ -49,10 +49,6 @@ class DisplayInfoProvider {
                        const api::system_display::DisplayProperties& info,
                        std::string* error) = 0;
 
-  // Get the screen that is always active, which will be used for monitoring
-  // display changes events.
-  virtual gfx::Screen* GetActiveScreen() = 0;
-
   // Enable the unified desktop feature.
   virtual void EnableUnifiedDesktop(bool enable);