add UMA to record if a page has distilled data.

components/dom_distiller/core/viewer.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 "components/dom_distiller/core/viewer.h"
 
 #include <string>
 #include <vector>
 
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
 #include "components/dom_distiller/core/distilled_page_prefs.h"
 #include "components/dom_distiller/core/dom_distiller_service.h"
 #include "components/dom_distiller/core/proto/distilled_article.pb.h"
 #include "components/dom_distiller/core/proto/distilled_page.pb.h"
 #include "components/dom_distiller/core/task_tracker.h"
 #include "components/dom_distiller/core/url_constants.h"
 #include "components/dom_distiller/core/url_utils.h"
 #include "grit/components_resources.h"
 #include "grit/components_strings.h"
@@ skipping 63 matching lines @@
     return kSerifCssClass;
   } else if (font_family == DistilledPagePrefs::MONOSPACE) {
     return kMonospaceCssClass;
   }
   return kSansSerifCssClass;
 }
 
 void EnsureNonEmptyTitleAndContent(std::string* title, std::string* content) {
   if (title->empty())
     *title = l10n_util::GetStringUTF8(IDS_DOM_DISTILLER_VIEWER_NO_DATA_TITLE);
+  UMA_HISTOGRAM_BOOLEAN("DomDistiller.PageHasDistilledData", !content->empty());
   if (content->empty()) {
     *content = l10n_util::GetStringUTF8(
         IDS_DOM_DISTILLER_VIEWER_NO_DATA_CONTENT);
   }
 }
 
 std::string ReplaceHtmlTemplateValues(
     const std::string& title,
     const std::string& content,
     const std::string& loading_indicator_class,
@@ skipping 148 matching lines @@
 }
 
 const std::string GetDistilledPageFontFamilyJs(
     DistilledPagePrefs::FontFamily font_family) {
   return "useFontFamily('" + GetJsFontFamily(font_family) + "');";
 }
 
 }  // namespace viewer
 
 }  // namespace dom_distiller