Disable fullscren fb optimization with sw mirroring.

cc/output/overlay_strategy_fullscreen.h

Index: cc/output/overlay_strategy_fullscreen.h
diff --git a/cc/output/overlay_strategy_fullscreen.h b/cc/output/overlay_strategy_fullscreen.h
index 4100d253ba57ff84642d4163a5651bcd13794bbc..1429985874aeea49478bf48b1a330907a99fabb5 100644
--- a/cc/output/overlay_strategy_fullscreen.h
+++ b/cc/output/overlay_strategy_fullscreen.h
@@ -16,7 +16,8 @@ class OverlayCandidateValidator;
 // should be possible to use it as such.
 class CC_EXPORT OverlayStrategyFullscreen : public OverlayProcessor::Strategy {
  public:
-  OverlayStrategyFullscreen();
+  explicit OverlayStrategyFullscreen(
+      OverlayCandidateValidator* capability_checker);
   ~OverlayStrategyFullscreen() override;
 
   bool Attempt(ResourceProvider* resource_provider,
@@ -24,6 +25,8 @@ class CC_EXPORT OverlayStrategyFullscreen : public OverlayProcessor::Strategy {
                OverlayCandidateList* candidate_list) override;
 
  private:
+  OverlayCandidateValidator* capability_checker_;  // Weak.
+
   DISALLOW_COPY_AND_ASSIGN(OverlayStrategyFullscreen);
 };