Measure time spent during StrictMode violations.

chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationUIManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationUIManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationUIManager.java b/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationUIManager.java
index d75b12692d48fd0fcce753315dc13cdc20af94f8..5597c0d9d2215a29efd7cb97fcb10b033057c544 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationUIManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationUIManager.java
@@ -14,6 +14,7 @@ import android.graphics.Bitmap;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.StrictMode;
+import android.os.SystemClock;
 import android.text.Spannable;
 import android.text.SpannableStringBuilder;
 import android.text.TextUtils;
@@ -38,6 +39,7 @@ import org.chromium.chrome.browser.widget.RoundedIconGenerator;
 
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.util.concurrent.TimeUnit;
 
 import javax.annotation.Nullable;
 
@@ -494,7 +496,10 @@ public class NotificationUIManager {
         StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
         StrictMode.allowThreadDiskWrites();
         try {
+            long time = SystemClock.elapsedRealtime();
             mNotificationManager.notify(platformTag, PLATFORM_ID, notificationBuilder.build());
+            RecordHistogram.recordTimesHistogram("Android.StrictMode.NotificationUIBuildTime",
+                    SystemClock.elapsedRealtime() - time, TimeUnit.MILLISECONDS);
         } finally {
             StrictMode.setThreadPolicy(oldPolicy);
         }