Adds a /json/protocol endpoint to serve the DevTools protocol

content/browser/devtools/devtools_http_handler.h

Index: content/browser/devtools/devtools_http_handler.h
diff --git a/content/browser/devtools/devtools_http_handler.h b/content/browser/devtools/devtools_http_handler.h
index 5989da0188106475a4ff5718946e27b4a74a5a56..72836212cb5cc039ab7ceeb419bcc880b8554880 100644
--- a/content/browser/devtools/devtools_http_handler.h
+++ b/content/browser/devtools/devtools_http_handler.h
@@ -98,6 +98,8 @@ class DevToolsHttpHandler {
   void AcceptWebSocket(int connection_id,
                        const net::HttpServerRequestInfo& request);
 
+  void DecompressAndSendJsonProtocol(int connection_id);
+
   // Returns the front end url without the host at the beginning.
   std::string GetFrontendURLInternal(const std::string& target_id,
                                      const std::string& host);