Adds missing OfflinePage downloads metrics reporting

This change also splits the reporting of offline page counts between
prefetched and non-prefetched.

Bug: 896095, 894643
Change-Id: Ic3bfc53ecd2558df1b349af66bbe7d3f88bd6531
Reviewed-on: https://chromium-review.googlesource.com/c/1285750Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601015}

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java

@@ -1128,6 +1128,15 @@ public class DownloadUtils {
         return item.getDownloadInfo().getLastAccessTime() != 0;
     }
 
+    /**
+     * Returns |true| if the offline item is not null and has already been viewed by the user.
+     * @param offlineItem The offline item to check.
+     * @return true if the item is valid has been viewed by the user.
+     */
+    public static boolean isOfflineItemViewed(OfflineItem offlineItem) {
+        return offlineItem != null && offlineItem.lastAccessedTimeMs > offlineItem.completionTimeMs;
+    }
+
     /**
      * Given two timestamps, calculates if both occur on the same date.
      * @return True if they belong in the same day. False otherwise.

chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryAdapter.java

@@ -36,7 +36,6 @@ import org.chromium.components.download.DownloadState;
 import org.chromium.components.offline_items_collection.ContentId;
 import org.chromium.components.offline_items_collection.OfflineContentProvider;
 import org.chromium.components.offline_items_collection.OfflineItem;
-import org.chromium.components.offline_items_collection.OfflineItemFilter;
 import org.chromium.components.offline_items_collection.OfflineItemState;
 import org.chromium.components.variations.VariationsAssociatedData;
 
@@ -817,17 +816,34 @@ public class DownloadHistoryAdapter
     }
 
     private void recordOfflineItemCountHistograms() {
-        int[] itemCounts = new int[OfflineItemFilter.FILTER_BOUNDARY];
-        for (DownloadHistoryItemWrapper item : mOfflineItems) {
-            OfflineItemWrapper offlineItem = (OfflineItemWrapper) item;
-            if (offlineItem.isOffTheRecord()) continue;
-            itemCounts[offlineItem.getOfflineItemFilter()]++;
+        int offlinePageCount = 0;
+        int viewedOfflinePageCount = 0;
+        int prefetchedOfflinePageCount = 0;
+        int viewedPrefetchedOfflinePageCount = 0;
+
+        for (DownloadHistoryItemWrapper itemWrapper : mOfflineItems) {
+            if (itemWrapper.isOffTheRecord()) continue;
+            OfflineItemWrapper offlineItemWrapper = (OfflineItemWrapper) itemWrapper;
+            boolean hasBeenViewed = DownloadUtils.isOfflineItemViewed(offlineItemWrapper.getItem());
+            if (offlineItemWrapper.isSuggested()) {
+                prefetchedOfflinePageCount++;
+                if (hasBeenViewed) viewedPrefetchedOfflinePageCount++;
+            } else {
+                offlinePageCount++;
+                if (hasBeenViewed) viewedOfflinePageCount++;
+            }
         }
 
-        // TODO(shaktisahu): UMA for initial counts of offline pages, regular downloads and download
-        // file types and file extensions.
-        RecordHistogram.recordCountHistogram("Android.DownloadManager.InitialCount.OfflinePage",
-                itemCounts[OfflineItemFilter.FILTER_PAGE]);
+        RecordHistogram.recordCountHistogram(
+                "Android.DownloadManager.InitialCount.OfflinePage", offlinePageCount);
+        RecordHistogram.recordCountHistogram(
+                "Android.DownloadManager.InitialCount.Viewed.OfflinePage", viewedOfflinePageCount);
+        RecordHistogram.recordCountHistogram(
+                "Android.DownloadManager.InitialCount.PrefetchedOfflinePage",
+                prefetchedOfflinePageCount);
+        RecordHistogram.recordCountHistogram(
+                "Android.DownloadManager.InitialCount.Viewed.PrefetchedOfflinePage",
+                viewedPrefetchedOfflinePageCount);
     }
 
     @Override

tools/metrics/histograms/histograms.xml

@@ -122847,6 +122847,7 @@ uploading your change for review.
   <suffix name="Image"/>
   <suffix name="OfflinePage"/>
   <suffix name="Other"/>
+  <suffix name="PrefetchedOfflinePage"/>
   <suffix name="Total"/>
   <suffix name="Video"/>
   <affected-histogram name="Android.DownloadManager.InitialCount"/>