DisplayCompositor should enforce invariant that frame size and device scale factor are fixed

content/browser/renderer_host/delegated_frame_host.h

Index: content/browser/renderer_host/delegated_frame_host.h
diff --git a/content/browser/renderer_host/delegated_frame_host.h b/content/browser/renderer_host/delegated_frame_host.h
index 0cba4c46a9ee6d4a2c640f0707efccb85e6a9c52..e1f09e5911a9cf5494aedfee77fdb4fe56329d6f 100644
--- a/content/browser/renderer_host/delegated_frame_host.h
+++ b/content/browser/renderer_host/delegated_frame_host.h
@@ -13,6 +13,7 @@
 #include "cc/output/copy_output_result.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/compositor_frame_sink_support_client.h"
+#include "content/browser/bad_message.h"
 #include "content/browser/compositor/image_transport_factory.h"
 #include "content/browser/compositor/owned_mailbox.h"
 #include "content/browser/renderer_host/delegated_frame_evictor.h"
@@ -77,6 +78,8 @@ class CONTENT_EXPORT DelegatedFrameHostClient {
 
   virtual void SetBeginFrameSource(cc::BeginFrameSource* source) = 0;
   virtual bool IsAutoResizeEnabled() const = 0;
+
+  virtual void ReceivedBadMessage(bad_message::BadMessageReason reason) {}
 };
 
 // The DelegatedFrameHost is used to host all of the RenderWidgetHostView state
@@ -120,6 +123,7 @@ class CONTENT_EXPORT DelegatedFrameHost
   void ReclaimResources(const cc::ReturnedResourceArray& resources) override;
   void WillDrawSurface(const cc::LocalSurfaceId& id,
                        const gfx::Rect& damage_rect) override;
+  void OnBadFrameReceived() override;
 
   // Public interface exposed to RenderWidgetHostView.