[Android] spellcheck: add latency UMA.

components/spellcheck/browser/spellchecker_session_bridge_android.cc

Index: components/spellcheck/browser/spellchecker_session_bridge_android.cc
diff --git a/components/spellcheck/browser/spellchecker_session_bridge_android.cc b/components/spellcheck/browser/spellchecker_session_bridge_android.cc
index 5c2644f8ecc3c85e211fd8aa0f4081aec66651df..3a21fe0275f2261530815cf0b9ef570c77e5eef5 100644
--- a/components/spellcheck/browser/spellchecker_session_bridge_android.cc
+++ b/components/spellcheck/browser/spellchecker_session_bridge_android.cc
@@ -9,6 +9,8 @@
 
 #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"
@@ -122,6 +124,16 @@ void SpellCheckerSessionBridge::DisconnectSession() {
   }
 }
 
+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,