Headless: Support sending and receiving of raw protocol messages

headless/public/headless_devtools_client.h

Index: headless/public/headless_devtools_client.h
diff --git a/headless/public/headless_devtools_client.h b/headless/public/headless_devtools_client.h
index 573336af792ea6e3334851fbd1b648b85bf06476..7e7d97982c5c02bda5a925cf7be8a455384f90e9 100644
--- a/headless/public/headless_devtools_client.h
+++ b/headless/public/headless_devtools_client.h
@@ -146,6 +146,31 @@ class HEADLESS_EXPORT HeadlessDevToolsClient {
   virtual target::Domain* GetTarget() = 0;
   virtual tracing::Domain* GetTracing() = 0;
 
+  class HEADLESS_EXPORT RawProtocolListener {
+   public:
+    RawProtocolListener() {}
+    virtual ~RawProtocolListener() {}
+
+    // Returns true if the listener handled the message.
+    virtual bool OnProtocolMessage(
+        const std::string& devtools_agent_host_id,
+        const std::string& json_message,
+        const base::DictionaryValue& parsed_message) = 0;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(RawProtocolListener);
+  };
+
+  virtual void SetRawProtocolListener(
+      RawProtocolListener* raw_protocol_listener) = 0;
+
+  // Generates an odd numbered ID.
+  virtual int GetNextRawDevToolsMessageId() = 0;
+
+  // The id within the message must be odd to prevent collisions.
+  virtual void SendRawDevToolsMessage(const std::string& json_message) = 0;
+  virtual void SendRawDevToolsMessage(const base::DictionaryValue& message) = 0;
+
   // TODO(skyostil): Add notification for disconnection.
 
  private: