[ManageSpace] Record histogram of user's web storage size

Bug: 875439
Change-Id: If6c56a4c634ce685a4e1ab93660ae95db7d90716
Reviewed-on: https://chromium-review.googlesource.com/c/1274599Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599380}

chrome/android/java/src/org/chromium/chrome/browser/preferences/website/ManageSpaceActivity.java

@@ -40,6 +40,7 @@ import org.chromium.chrome.browser.preferences.Preferences;
 import org.chromium.chrome.browser.preferences.PreferencesLauncher;
 import org.chromium.chrome.browser.preferences.website.Website.StoredDataClearedCallback;
 import org.chromium.chrome.browser.searchwidget.SearchWidgetProvider;
+import org.chromium.chrome.browser.util.ConversionUtils;
 
 import java.util.Collection;
 
@@ -274,6 +275,10 @@ public class ManageSpaceActivity extends AppCompatActivity implements View.OnCli
     }
 
     private void onSiteStorageSizeCalculated(long totalSize, long unimportantSize) {
+        RecordHistogram.recordCountHistogram("Android.ManageSpace.TotalDiskUsageMB",
+                (int) ConversionUtils.bytesToMegabytes(totalSize));
+        RecordHistogram.recordCountHistogram("Android.ManageSpace.UnimportantDiskUsageMB",
+                (int) ConversionUtils.bytesToMegabytes(unimportantSize));
         mSiteDataSizeText.setText(Formatter.formatFileSize(this, totalSize));
         mUnimportantSiteDataSizeText.setText(Formatter.formatFileSize(this, unimportantSize));
     }

tools/metrics/histograms/histograms.xml

@@ -1939,6 +1939,24 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="Android.ManageSpace.TotalDiskUsageMB" units="MB">
+  <owner>dmurph@chromium.org</owner>
+  <summary>
+    Recorded when the user opens the 'Manage Space' screen for Chrome, after the
+    disk usage is calculated. The disk usage value represents the accumulated
+    disk usage by websites.
+  </summary>
+</histogram>
+
+<histogram name="Android.ManageSpace.UnimportantDiskUsageMB" units="MB">
+  <owner>dmurph@chromium.org</owner>
+  <summary>
+    Recorded when the user opens the 'Manage Space' screen for Chrome, after the
+    disk usage is calculated. The disk usage value represents the accumulated
+    disk usage by websites that are not considered 'important'.
+  </summary>
+</histogram>
+
 <histogram name="Android.MemoryPressureMonitor.GetMyMemoryState.Failed.Time"
     units="microseconds">
   <owner>dskiba@chromium.org</owner>