Give URLRequestJobFactory::Interceptors the ability to specify protocols they handle.

net/url_request/url_request_job_factory.h

Index: net/url_request/url_request_job_factory.h
diff --git a/net/url_request/url_request_job_factory.h b/net/url_request/url_request_job_factory.h
index 594883aad9825073b9cea355a77e4afdc0a501c6..176830d9bd22b20d794263bbb9fb96a4a387b918 100644
--- a/net/url_request/url_request_job_factory.h
+++ b/net/url_request/url_request_job_factory.h
@@ -57,6 +57,13 @@ class URLRequestJobFactory : public base::NonThreadSafe {
     // returned.
     virtual URLRequestJob* MaybeInterceptResponse(
         URLRequest* request) const = 0;
+
+    // Returns true if this interceptor handles requests for URLs with the
+    // given protocol. Returning false does not imply that this interceptor
+    // can't or won't handle requests with the given protocol.
+    virtual bool WillHandleProtocol(const std::string& protocol) const {
+        return false;
+    }
   };
 
   URLRequestJobFactory();