Add a WebDocument::watchCssSelectors(selectors)

public/web/WebFrameClient.h

Index: public/web/WebFrameClient.h
diff --git a/public/web/WebFrameClient.h b/public/web/WebFrameClient.h
index 5e21a0423a37b028824bc5d4a2efeed023590e3b..b67f2935ab20221ce4eb8a0e3adebade923b797b 100644
--- a/public/web/WebFrameClient.h
+++ b/public/web/WebFrameClient.h
@@ -124,6 +124,9 @@ public:
     // This frame's name has changed.
     virtual void didChangeName(WebFrame*, const WebString&) { }
 
+    // Called when a watched CSS selector matches or stops matching.
+    virtual void didMatchCSS(WebFrame*, const WebVector<WebString>& newlyMatchingSelectors, const WebVector<WebString>& stoppedMatchingSelectors) { }

[esprehn, 2013/09/04 06:08:28]

Passing the frame into didMatchCSS is really weird, WebDocument already knows
it's frame, you shouldn't pass one since that just means you can potentially get
the wrong one.

[Jeffrey Yasskin, 2013/09/12 22:09:59]

There's no WebDocument here though, and the WebFrameClient might be a
RenderViewImpl, which is the client for more than one WebFrame.  I need some way
in this callback to figure out which one.

+
     // Load commands -------------------------------------------------------
 
     // The client should handle the navigation externally.