Add SetSupportsQuic method to explicitly specify server that supports QUIC.

components/cronet/android/chromium_url_request.cc

Index: components/cronet/android/chromium_url_request.cc
diff --git a/components/cronet/android/chromium_url_request.cc b/components/cronet/android/chromium_url_request.cc
index be31c17ed5c5d74534a425e8c42781f8074c84b5..7239931fdb64e555586622fc53c23e75e4d1f78a 100644
--- a/components/cronet/android/chromium_url_request.cc
+++ b/components/cronet/android/chromium_url_request.cc
@@ -387,4 +387,16 @@ static void GetAllHeaders(JNIEnv* env,
       env, object, headersMap, NULL, status_line.Release());
 }
 
+static jstring GetNegotiatedProtocol(JNIEnv* env,
+                                     jobject object,
+                                     jlong urlRequestAdapter) {
+  URLRequestAdapter* request =
+      reinterpret_cast<URLRequestAdapter*>(urlRequestAdapter);
+  if (request == NULL) {

[mmenke, 2014/09/09 14:53:35]

Looks like we're pretty inconsistent about checking this.  (See, for example,
AppendChunk, GetErrorString, and GetHttpStatusCode).  If it can't happen, we
shouldn't be checking for it.  If it can, we should be more consistent (And have
tests).

[mef, 2014/09/10 16:48:17]

Acknowledged. I think we should have these checks everywhere, but I'm not sure
whether that belongs to this CL.

+    return NULL;
+  }
+  std::string negotiated_protocol = request->GetNegotiatedProtocol();

[mmenke, 2014/09/09 14:53:35]

If we haven't negotiated a protocol yet, I assume this is an empty string?  If
so, think we should also be returning that in the request==NULL case, if that
code is worth having (I'm skeptical that it is, unless it can actually happen -
and if it can, we should probably be throwing exceptions, actually).

[mef, 2014/09/10 16:48:17]

Done.

+  return ConvertUTF8ToJavaString(env, negotiated_protocol.c_str()).Release();
+}
+
 }  // namespace cronet