compositor-worker: cc->blink mutation plumbing

third_party/WebKit/public/web/WebWidget.h

-
 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 33 matching lines @@
 #include "WebTextDirection.h"
 #include "WebTextInputInfo.h"
 
 namespace blink {
 
 class WebCompositeAndReadbackAsyncCallback;
 class WebInputEvent;
 class WebLayoutAndPaintAsyncCallback;
 class WebPagePopup;
 class WebString;
+struct WebCompositorMutations;
 struct WebPoint;
 template <typename T> class WebVector;
 
 class WebWidget {
 public:
     // This method closes and deletes the WebWidget.
     virtual void close() { }
 
     // Returns the current size of the WebWidget.
     virtual WebSize size() { return WebSize(); }
@@ skipping 76 matching lines @@
         float topControlsShownRatioDelta) { }
 
     // Records composite or render events for the Performance Timeline.
     // See http://w3c.github.io/frame-timing/ for definition of terms.
     enum FrameTimingEventType {
         CompositeEvent,
         RenderEvent,
     };
     virtual void recordFrameTimingEvent(FrameTimingEventType eventType, int64_t RectId, const WebVector<WebFrameTimingEvent>& events) { }
 
+    // Called to notify the WebWidget about the mutations made to the elements from a compositor worker.
+    virtual void applyMutations(const WebCompositorMutations&) {}

[jbroman, 2016/01/23 23:55:10]

nit: Would you mind including "compositor" or similar in the method name? It's
not obvious until you look at the parameters that this has to do with
compositing (as opposed to mutating some other aspect of a widget).

I'm not a public/ owner, but since this CL already requires that
cc::LayerTreeMutations be used within public/, why not just forward-declare and
say "const cc::LayerTreeMutations&"? That class already has the same virtual
members. (It also avoids having to actually include the cc header, unlike
subclassing.) Ignore if a public OWNER overrules me. :)

[majidvp, 2016/01/25 20:40:11]

Done.
Happy to change if that is desirable. My impression after looking at recent
similar CLs
is that it is still desirable to define a type in Blink  by extending the CC
type [1].

[1]
https://chromium.googlesource.com/chromium/src/+/0536dbbcab956b879d2bee49f7e4...

+
     // Called to inform the WebWidget that mouse capture was lost.
     virtual void mouseCaptureLost() { }
 
     // Called to inform the WebWidget that it has gained or lost keyboard focus.
     virtual void setFocus(bool) { }
 
     // Called to inform the WebWidget of a new composition text.
     // If selectionStart and selectionEnd has the same value, then it indicates
     // the input caret position. If the text is empty, then the existing
     // composition text will be cancelled.
@@ skipping 103 matching lines @@
     // control what are valid states for top controls and if it should animate.
     virtual void updateTopControlsState(WebTopControlsState constraints, WebTopControlsState current, bool animate) { }
 
 protected:
     ~WebWidget() { }
 };
 
 } // namespace blink
 
 #endif