[Manifest] Add metrics recording.

content/renderer/manifest/manifest_uma_util.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/renderer/manifest/manifest_uma_util.h"
+
+#include "base/metrics/histogram.h"
+#include "content/public/common/manifest.h"
+
+namespace content {
+
+void ManifestUmaUtil::ParsedManifest(const Manifest& manifest) {
+  UMA_HISTOGRAM_BOOLEAN("Manifest.IsEmpty", manifest.IsEmpty());

[Miguel Garcia, 2014/10/02 14:26:46]

you could early return here if it's empty.

[mlamouri (slow - plz ping), 2014/10/02 15:35:06]

Done.

+  UMA_HISTOGRAM_BOOLEAN("Manifest.name", !manifest.name.is_null());
+  UMA_HISTOGRAM_BOOLEAN("Manifest.short_name", !manifest.short_name.is_null());
+  UMA_HISTOGRAM_BOOLEAN("Manifest.start_url", !manifest.start_url.is_empty());
+  UMA_HISTOGRAM_BOOLEAN("Manifest.display",
+      manifest.display != Manifest::DISPLAY_MODE_UNSPECIFIED);
+  UMA_HISTOGRAM_BOOLEAN("Manifest.orientation",
+      manifest.orientation != blink::WebScreenOrientationLockDefault);
+  UMA_HISTOGRAM_BOOLEAN("Manifest.icons", !manifest.icons.empty());
+  UMA_HISTOGRAM_BOOLEAN("Manifest.gcm_sender_id",
+      !manifest.gcm_sender_id.is_null());

[Miguel Garcia, 2014/10/02 14:26:46]

what if it's empty?

[mlamouri (slow - plz ping), 2014/10/02 15:35:06]

It will be null if the value was not present of failed to be parsed. If the
value was set to the empty string, it is considered present. I don't think we
should try to special case that.

+}
+
+void ManifestUmaUtil::FetchSucceeded() {
+  UMA_HISTOGRAM_BOOLEAN("Manifest.FetchSuccess", true);
+}
+
+void ManifestUmaUtil::FetchFailed() {
+  UMA_HISTOGRAM_BOOLEAN("Manifest.FetchSuccess", false);
+}
+
+} // namespace content