[DevTools] Filter any messages from previous sessions in DevToolsAgentHostImpl

content/renderer/devtools/devtools_agent.h

Index: content/renderer/devtools/devtools_agent.h
diff --git a/content/renderer/devtools/devtools_agent.h b/content/renderer/devtools/devtools_agent.h
index 7b1200ba98d09cfd296947db2ebb261d8dc4fa5f..865fc0fd8b52a9efe036f8f87d51792247ce0ff7 100644
--- a/content/renderer/devtools/devtools_agent.h
+++ b/content/renderer/devtools/devtools_agent.h
@@ -33,12 +33,12 @@ class CONTENT_EXPORT DevToolsAgent
   // Returns agent instance for its routing id.
   static DevToolsAgent* FromRoutingId(int routing_id);
 
-  static void SendChunkedProtocolMessage(
-      IPC::Sender* sender,
-      int routing_id,
-      int call_id,
-      const std::string& message,
-      const std::string& post_state);
+  static void SendChunkedProtocolMessage(IPC::Sender* sender,
+                                         int routing_id,
+                                         int session_id,
+                                         int call_id,
+                                         const std::string& message,
+                                         const std::string& post_state);
 
   blink::WebDevToolsAgent* GetWebAgent();
 
@@ -55,7 +55,8 @@ class CONTENT_EXPORT DevToolsAgent
   void WidgetWillClose() override;
 
   // WebDevToolsAgentClient implementation.
-  void sendProtocolMessage(int call_id,
+  void sendProtocolMessage(int session_id,
+                           int call_id,
                            const blink::WebString& response,
                            const blink::WebString& state) override;
   blink::WebDevToolsAgentClient::WebKitClientMessageLoop*
@@ -66,12 +67,16 @@ class CONTENT_EXPORT DevToolsAgent
   void enableTracing(const blink::WebString& category_filter) override;
   void disableTracing() override;
 
-  void OnAttach(const std::string& host_id);
+  void OnAttach(const std::string& host_id, int session_id);
   void OnReattach(const std::string& host_id,
+                  int session_id,
                   const std::string& agent_state);
   void OnDetach();
-  void OnDispatchOnInspectorBackend(const std::string& message);
-  void OnInspectElement(const std::string& host_id, int x, int y);
+  void OnDispatchOnInspectorBackend(int session_id, const std::string& message);
+  void OnInspectElement(const std::string& host_id,
+                        int session_id,
+                        int x,
+                        int y);
   void ContinueProgram();
   void OnSetupDevToolsClient(const std::string& compatibility_script);