DevTools: introduce browser domain for basic target discovery.

content/public/browser/devtools_agent_host.h

Index: content/public/browser/devtools_agent_host.h
diff --git a/content/public/browser/devtools_agent_host.h b/content/public/browser/devtools_agent_host.h
index c4b8bc0d0dc8abdc0141eefbbb05ded30f6cb16e..7127e6d24b11b3cc762106eefbef4d1c0fc443aa 100644
--- a/content/public/browser/devtools_agent_host.h
+++ b/content/public/browser/devtools_agent_host.h
@@ -108,11 +108,15 @@ class CONTENT_EXPORT DevToolsAgentHost
   // Returns all possible DevToolsAgentHosts.
   static List GetOrCreateAll();
 
-  // Client attaches to this agent host to start debugging it.
-  virtual void AttachClient(DevToolsAgentHostClient* client) = 0;
+  // Attaches |client| to this agent host to start debugging.

[dgozman, 2016/06/08 03:53:29]

Let's comment when this may return false.

[pfeldman, 2016/06/08 15:54:52]

Done.

+  virtual bool AttachClient(DevToolsAgentHostClient* client) = 0;
+
+  // Attaches |client| to this agent host to start debugging. Disconnects
+  // any existing clients.
+  virtual bool ForceAttachClient(DevToolsAgentHostClient* client) = 0;

[dgozman, 2016/06/08 03:53:29]

Can this ever return false?

[pfeldman, 2016/06/08 15:54:53]

Done.

 
   // Already attached client detaches from this agent host to stop debugging it.
-  virtual void DetachClient() = 0;
+  virtual bool DetachClient(DevToolsAgentHostClient* client) = 0;
 
   // Returns true if there is a client attached.
   virtual bool IsAttached() = 0;