[Android] spellcheck: add latency UMA.

components/spellcheck/browser/spellchecker_session_bridge_android.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SPELLCHECK_BROWSER_SPELLCHECKER_SESSION_BRIDGE_ANDROID_H_
 #define COMPONENTS_SPELLCHECK_BROWSER_SPELLCHECKER_SESSION_BRIDGE_ANDROID_H_
 
 #include <jni.h>
 
 #include <memory>
@@ skipping 19 matching lines @@
                         const base::string16& text);
 
   // Receives information from Java side about the typos in a given string
   // of text, processes these and sends them to the renderer.
   void ProcessSpellCheckResults(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& jobj,
       const base::android::JavaParamRef<jintArray>& offset_array,
       const base::android::JavaParamRef<jintArray>& length_array);
 
+  void RecordLatencyUMA(JNIEnv* env,
+                        const base::android::JavaParamRef<jobject>& jobj,
+                        long latencyMs);
+
   // Sets the handle to the Java SpellCheckerSessionBridge object to null,
   // marking the Java object for garbage collection.
   void DisconnectSession();
 
  private:
   struct SpellingRequest {
     SpellingRequest(int route_id, int identifier, const base::string16& text);
     ~SpellingRequest();
 
     int route_id;
     int identifier;
     base::string16 text;
   };
 
   int render_process_id_;
 
   std::unique_ptr<SpellingRequest> active_request_;
   std::unique_ptr<SpellingRequest> pending_request_;
 
   base::android::ScopedJavaGlobalRef<jobject> java_object_;
   bool java_object_initialization_failed_;
 
   DISALLOW_COPY_AND_ASSIGN(SpellCheckerSessionBridge);
 };
 
 #endif  // COMPONENTS_SPELLCHECK_BROWSER_SPELLCHECKER_SESSION_BRIDGE_ANDROID_H_