Add dedicated windowToViewport method

third_party/WebKit/public/web/WebWidgetClient.h

Index: third_party/WebKit/public/web/WebWidgetClient.h
diff --git a/third_party/WebKit/public/web/WebWidgetClient.h b/third_party/WebKit/public/web/WebWidgetClient.h
index eb6fe66a322a22bf0bf9ed199de9f61534d67cea..6497e9133e47621be7ba6d212929b2fb0cd5ac50 100644
--- a/third_party/WebKit/public/web/WebWidgetClient.h
+++ b/third_party/WebKit/public/web/WebWidgetClient.h
@@ -48,6 +48,7 @@ class WebString;
 class WebWidget;
 struct WebCursorInfo;
 struct WebFloatPoint;
+struct WebFloatRect;
 struct WebFloatSize;
 struct WebSize;
 
@@ -177,6 +178,13 @@ public:
     // TODO(oshima): Update the comment when the migration is completed.
     virtual void convertViewportToWindow(WebRect* rect) {}

[dgozman, 2016/01/26 00:17:45]

Perhaps, this one should work with WebFloatRect as well? Or is it deliberately
left as WebRect?
This does not affect this patch though.

[oshima, 2016/01/26 00:24:00]

Sorry I forgot to mention. Yes, I'm going to change this
(https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/r...)

 
+    // Converts the |rect| from the coordinates in native window in
+    // DIP to Blink's Viewport coordinates. They're identical in
+    // tradional world, but will differ when use-zoom-for-dsf feature
+    // is eanbled.  TODO(oshima): Update the comment when the
+    // migration is completed.
+    virtual void convertWindowToViewport(WebFloatRect* rect) {}
+
 protected:
     ~WebWidgetClient() { }
 };