[Android] spellcheck: add latency UMA.

components/spellcheck/browser/spellchecker_session_bridge_android.cc

 // 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.
 
 #include "components/spellcheck/browser/spellchecker_session_bridge_android.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/time/time.h"
 #include "components/spellcheck/common/spellcheck_messages.h"
 #include "components/spellcheck/common/spellcheck_result.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "jni/SpellCheckerSessionBridge_jni.h"
 
 using base::android::JavaParamRef;
 
 SpellCheckerSessionBridge::SpellCheckerSessionBridge(int render_process_id)
     : render_process_id_(render_process_id),
@@ skipping 93 matching lines @@
   active_request_.reset();
   pending_request_.reset();
 
   if (!java_object_.is_null()) {
     Java_SpellCheckerSessionBridge_disconnect(
         base::android::AttachCurrentThread(), java_object_);
     java_object_.Reset();
   }
 }
 
+void SpellCheckerSessionBridge::RecordLatencyUMA(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& jobj,
+    long latencyMs) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK(latencyMs >= 0);
+  UMA_HISTOGRAM_TIMES("SpellCheck.Android.Latency",
+                      base::TimeDelta::FromMilliseconds(latencyMs));

[Ilya Sherman, 2016/10/28 18:53:54]

Hmm, why are you adding a native call for recording this histogram, rather than
using the Java API to record the histogram?  (If you were simply unaware that
API exists -- it does! =))

[timvolodine, 2016/11/01 17:14:23]

yeey it does! (didn't realize it is available now, so did my own plumbing).
anyways removed the native side completely.

+}
+
 SpellCheckerSessionBridge::SpellingRequest::SpellingRequest(
     int route_id,
     int identifier,
     const base::string16& text)
     : route_id(route_id), identifier(identifier), text(text) {}
 
 SpellCheckerSessionBridge::SpellingRequest::~SpellingRequest() {}