Put Data Reduction Proxy support in Cronet behind a gyp flag

components/cronet/android/test/native_test_server.cc

Index: components/cronet/android/test/native_test_server.cc
diff --git a/components/cronet/android/test/native_test_server.cc b/components/cronet/android/test/native_test_server.cc
index 88f150fe93b89da11a2a577b0035531ff1b37e69..9003b64aa55f2c25840c659191deddb6d98fcf96 100644
--- a/components/cronet/android/test/native_test_server.cc
+++ b/components/cronet/android/test/native_test_server.cc
@@ -306,6 +306,14 @@ jstring GetHostPort(JNIEnv* env, jclass jcaller) {
   return base::android::ConvertUTF8ToJavaString(env, host_port).Release();
 }
 
+jboolean IsDataReductionProxySupported(JNIEnv* env, jclass jcaller) {
+#if defined(DATA_REDUCTION_PROXY_SUPPORT)
+  return JNI_TRUE;
+#else
+  return JNI_FALSE;
+#endif
+}
+
 bool RegisterNativeTestServer(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }