[Crash Reporting] Add local histogram to debug missing chrome:crashes entries.

BUG=772159
R=mark@chromium.org

Change-Id: I596b085a93b0dde4717f03db2e5d2cd4cd2fec82
Reviewed-on: https://chromium-review.googlesource.com/703919Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Ilya Sherman <isherman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506930}

chrome/browser/crash_upload_list/crash_upload_list_android.cc

@@ -11,9 +11,34 @@
 #include "base/files/file.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_util.h"
+#include "base/metrics/histogram_macros_local.h"
 #include "jni/MinidumpUploadService_jni.h"
 #include "ui/base/text/bytes_formatting.h"
 
+namespace {
+
+enum class UnsuccessfulUploadListState {
+  FORCED,
+  PENDING,
+  NOT_UPLOADED,
+  OTHER_FILENAME_SUFFIX,
+  FAILED_TO_LOAD_FILE_INFO,
+  FAILED_TO_LOAD_FILE_SIZE,
+  FAILED_TO_FIND_DASH,
+  ADDING_AN_UPLOAD_ENTRY,
+  COUNT
+};
+
+// TODO(isherman): This is a temporary histogram for debugging
+// [ https://crbug.com/772159 ] and should be removed once that bug is closed.
+void RecordUnsuccessfulUploadListState(UnsuccessfulUploadListState state) {
+  LOCAL_HISTOGRAM_ENUMERATION(
+      "Debug.Crash.Android.LoadUnsuccessfulUploadListState", state,
+      UnsuccessfulUploadListState::COUNT);
+}
+
+}  // namespace
+
 CrashUploadListAndroid::CrashUploadListAndroid(
     const base::FilePath& upload_log_path)
     : TextLogUploadList(upload_log_path) {}
@@ -46,23 +71,35 @@ void CrashUploadListAndroid::LoadUnsuccessfulUploadList(
   for (base::FilePath file = files.Next(); !file.empty(); file = files.Next()) {
     UploadList::UploadInfo::State upload_state;
     if (file.value().find(manually_forced_uploads) != std::string::npos) {
+      RecordUnsuccessfulUploadListState(UnsuccessfulUploadListState::FORCED);
       upload_state = UploadList::UploadInfo::State::Pending_UserRequested;
     } else if (file.value().find(pending_uploads) != std::string::npos) {
+      RecordUnsuccessfulUploadListState(UnsuccessfulUploadListState::PENDING);
       upload_state = UploadList::UploadInfo::State::Pending;
     } else if (file.value().find(skipped_uploads) != std::string::npos) {
+      RecordUnsuccessfulUploadListState(
+          UnsuccessfulUploadListState::NOT_UPLOADED);
       upload_state = UploadList::UploadInfo::State::NotUploaded;
     } else {
       // The |file| is something other than a minidump file, e.g. a logcat file.
+      RecordUnsuccessfulUploadListState(
+          UnsuccessfulUploadListState::OTHER_FILENAME_SUFFIX);
       continue;
     }
 
     base::File::Info info;
-    if (!base::GetFileInfo(file, &info))
+    if (!base::GetFileInfo(file, &info)) {
+      RecordUnsuccessfulUploadListState(
+          UnsuccessfulUploadListState::FAILED_TO_LOAD_FILE_INFO);
       continue;
+    }
 
     int64_t file_size = 0;
-    if (!base::GetFileSize(file, &file_size))
+    if (!base::GetFileSize(file, &file_size)) {
+      RecordUnsuccessfulUploadListState(
+          UnsuccessfulUploadListState::FAILED_TO_LOAD_FILE_SIZE);
       continue;
+    }
 
     // Crash reports can have multiple extensions (e.g. foo.dmp, foo.dmp.try1,
     // foo.skipped.try0).
@@ -74,9 +111,14 @@ void CrashUploadListAndroid::LoadUnsuccessfulUploadList(
     // chromium-renderer-minidump-f297dbcba7a2d0bb.
     std::string id = file.value();
     std::size_t pos = id.find_last_of("-");
-    if (pos == std::string::npos)
+    if (pos == std::string::npos) {
+      RecordUnsuccessfulUploadListState(
+          UnsuccessfulUploadListState::FAILED_TO_FIND_DASH);
       continue;
+    }
 
+    RecordUnsuccessfulUploadListState(
+        UnsuccessfulUploadListState::ADDING_AN_UPLOAD_ENTRY);
     id = id.substr(pos + 1);
     UploadList::UploadInfo upload(id, info.creation_time, upload_state,
                                   ui::FormatBytes(file_size));