Added UMA for downloads that are interrupted at the end.

BUG=None
TEST=None


Review URL: http://codereview.chromium.org/7980018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@102189 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/download/download_stats.cc

@@ -61,7 +61,14 @@ void RecordDownloadInterrupted(int error, int64 received, int64 total) {
                                 1,
                                 kMaxKb,
                                 kBuckets);
-    if (delta_bytes >= 0) {
+    if (delta_bytes == 0) {
+      RecordDownloadCount(INTERRUPTED_AT_END_COUNT);
+      UMA_HISTOGRAM_CUSTOM_ENUMERATION(
+          "Download.InterruptedAtEndError",
+          -error,
+          base::CustomHistogram::ArrayToCustomRanges(
+              kAllNetErrorCodes, arraysize(kAllNetErrorCodes)));
+    } else if (delta_bytes > 0) {
       UMA_HISTOGRAM_CUSTOM_COUNTS("Download.InterruptedOverrunBytes",
                                   delta_bytes,
                                   1,

content/browser/download/download_stats.h

@@ -64,6 +64,9 @@ enum DownloadCountTypes {
   // Counts iterations of the BaseFile::AppendDataToFile() loop.
   WRITE_LOOP_COUNT,
 
+  // Counts interruptions that happened at the end of the download.
+  INTERRUPTED_AT_END_COUNT,
+
   DOWNLOAD_COUNT_TYPES_LAST_ENTRY
 };