Reland of: [Ozone-GBM] Handle GPU crashes

ui/ozone/platform/dri/screen_manager.h

Index: ui/ozone/platform/dri/screen_manager.h
diff --git a/ui/ozone/platform/dri/screen_manager.h b/ui/ozone/platform/dri/screen_manager.h
index 46cbd66133f48a8727fb1bbf212dc758f5191eb4..eeca56ae31e96174f868b931168226e099f67f09 100644
--- a/ui/ozone/platform/dri/screen_manager.h
+++ b/ui/ozone/platform/dri/screen_manager.h
@@ -29,13 +29,16 @@ class ScreenManager {
   ScreenManager(DriWrapper* dri, ScanoutBufferGenerator* surface_generator);
   virtual ~ScreenManager();
 
+  // Register a display controller. This must be called before trying to
+  // configure it.
+  void AddDisplayController(uint32_t crtc, uint32_t connector);
+
   // Remove a display controller from the list of active controllers. The
   // controller is removed since it was disconnected.
   void RemoveDisplayController(uint32_t crtc);
 
-  // Configure (and add if not present) a display controller. The display
-  // controller is identified by (|crtc|, |connector|) and the controller is
-  // modeset using |mode|.
+  // Configure a display controller. The display controller is identified by
+  // (|crtc|, |connector|) and the controller is modeset using |mode|.
   bool ConfigureDisplayController(uint32_t crtc,
                                   uint32_t connector,
                                   const gfx::Point& origin,
@@ -66,6 +69,11 @@ class ScreenManager {
   HardwareDisplayControllers::iterator FindActiveDisplayControllerByLocation(
       const gfx::Rect& bounds);
 
+  // Returns an iterator to the first controller located at |origin|. The
+  // controller may be disabled.
+  HardwareDisplayControllers::iterator FindDisplayControllerByLocation(
+      const gfx::Rect& bounds);
+
   // Perform modesetting in |controller| using |origin| and |mode|.
   bool ModesetDisplayController(HardwareDisplayController* controller,
                                 const gfx::Point& origin,