Record detailed breakdown of Reader Mode triggering

components/dom_distiller/content/renderer/distillability_agent.cc

 // Copyright 2015 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 "base/metrics/histogram.h"
 
 #include "components/dom_distiller/content/common/distiller_messages.h"
 #include "components/dom_distiller/content/renderer/distillability_agent.h"
 #include "components/dom_distiller/core/distillable_page_detector.h"
 #include "components/dom_distiller/core/experiments.h"
 #include "components/dom_distiller/core/page_features.h"
 #include "components/dom_distiller/core/url_utils.h"
 #include "content/public/renderer/render_frame.h"
 
 #include "third_party/WebKit/public/platform/WebDistillability.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebElement.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 
 namespace dom_distiller {
 
 using namespace blink;
 
 namespace {
 
 const char* const kBlacklist[] = {
   "www.reddit.com"
 };
 
+enum RejectionBuckets {
+  NOT_ARTICLE = 0,
+  MOBILE_FRIENDLY,
+  BLACKLISTED,
+  TOO_SHORT,
+  NOT_REJECTED,
+  REJECTION_BUCKET_BOUNDARY
+};
+
 // Returns whether it is necessary to send updates back to the browser.
 // The number of updates can be from 0 to 2. See the tests in
 // "distillable_page_utils_browsertest.cc".
 // Most heuristics types only require one update after parsing.
 // Adaboost is the only one doing the second update, which is after loading.
 bool NeedToUpdate(bool is_loaded) {
   switch (GetDistillerHeuristicsType()) {
     case DistillerHeuristicsType::ALWAYS_TRUE:
       return !is_loaded;
     case DistillerHeuristicsType::OG_ARTICLE:
@@ skipping 47 matching lines @@
   bool blacklisted = IsBlacklisted(parsed_url);
 
   int bucket = static_cast<unsigned>(features.isMobileFriendly) |
       (static_cast<unsigned>(distillable) << 1);
   if (is_last) {
     UMA_HISTOGRAM_ENUMERATION("DomDistiller.PageDistillableAfterLoading",
         bucket, 4);
   } else {
     UMA_HISTOGRAM_ENUMERATION("DomDistiller.PageDistillableAfterParsing",
         bucket, 4);
+    if (!distillable) {
+      UMA_HISTOGRAM_ENUMERATION("DomDistiller.DistillabilityRejection",
+          NOT_ARTICLE, REJECTION_BUCKET_BOUNDARY);
+    } else if (features.isMobileFriendly) {
+      UMA_HISTOGRAM_ENUMERATION("DomDistiller.DistillabilityRejection",
+          MOBILE_FRIENDLY, REJECTION_BUCKET_BOUNDARY);
+    } else if (blacklisted) {
+      UMA_HISTOGRAM_ENUMERATION("DomDistiller.DistillabilityRejection",
+          BLACKLISTED, REJECTION_BUCKET_BOUNDARY);
+    } else if (!long_article) {
+      UMA_HISTOGRAM_ENUMERATION("DomDistiller.DistillabilityRejection",
+          TOO_SHORT, REJECTION_BUCKET_BOUNDARY);
+    } else {
+      UMA_HISTOGRAM_ENUMERATION("DomDistiller.DistillabilityRejection",
+          NOT_REJECTED, REJECTION_BUCKET_BOUNDARY);
+    }
   }
 
   if (blacklisted) {
     return false;
   }
   if (features.isMobileFriendly) {
     return false;
   }
   return distillable && long_article;
 }
@@ skipping 40 matching lines @@
 
   bool is_last = IsLast(is_loaded);
   Send(new FrameHostMsg_Distillability(routing_id(),
       IsDistillablePage(doc, is_last), is_last));
 }
 
 
 DistillabilityAgent::~DistillabilityAgent() {}
 
 }  // namespace dom_distiller