[SH] Add common logging functions.

Bug: 1131107
Change-Id: Ib7b047409a42fe5a4ad5b33ecf10825214c9089d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2456126
Commit-Queue: sebsg <sebsg@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Reviewed-by: Cait Phillips <caitkp@chromium.org>
Reviewed-by: Sebastien Lalancette <seblalancette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817004}

components/BUILD.gn

@@ -139,6 +139,7 @@ test("components_unittests") {
     "//components/services/heap_profiling/public/cpp:unit_tests",
     "//components/services/unzip:unit_tests",
     "//components/sessions:unit_tests",
+    "//components/shared_highlighting/core/common:unit_tests",
     "//components/signin/core/browser:unit_tests",
     "//components/signin/internal/identity_manager:unit_tests",
     "//components/signin/public/base:unit_tests",
@@ -620,6 +621,7 @@ if (!is_ios && !is_fuchsia) {
       "//components/performance_manager:browser_tests",
       "//components/security_state/content",
       "//components/security_state/core",
+      "//components/shared_highlighting/core/common",
       "//components/strings",
       "//components/ukm:test_support",
       "//components/ukm/content",

components/shared_highlighting/core/common/BUILD.gn

@@ -3,5 +3,25 @@
 # found in the LICENSE file.
 
 static_library("common") {
-  sources = [ "shared_highlighting_metrics.h" ]
+  sources = [
+    "shared_highlighting_metrics.cc",
+    "shared_highlighting_metrics.h",
+  ]
+
+  deps = [
+    "//base",
+    "//components/search_engines:search_engine_utils",
+    "//services/metrics/public/cpp:metrics_cpp",
+  ]
+}
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [ "shared_highlighting_metrics_unittest.cc" ]
+  deps = [
+    "//base/test:test_support",
+    "//components/shared_highlighting/core/common",
+    "//testing/gtest",
+    "//url",
+  ]
 }

components/shared_highlighting/core/common/DEPS

+include_rules = [
+  "+base/metrics/histogram_functions.h",
+  "+components/search_engines/search_engine_utils.h",
+  "+services/metrics/public",
+  "+url",
+]
\ No newline at end of file

components/shared_highlighting/core/common/shared_highlighting_metrics.cc

+// Copyright 2020 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/shared_highlighting/core/common/shared_highlighting_metrics.h"
+
+#include "base/metrics/histogram_functions.h"
+#include "base/notreached.h"
+#include "components/search_engines/search_engine_utils.h"
+
+namespace shared_highlighting {
+
+namespace {
+
+TextFragmentLinkOpenSource GetLinkSource(const GURL& referrer) {
+  bool from_search_engine = SearchEngineUtils::GetEngineType(referrer) > 0;
+  return from_search_engine ? TextFragmentLinkOpenSource::kSearchEngine
+                            : TextFragmentLinkOpenSource::kUnknown;
+}
+
+}  // namespace
+
+void LogTextFragmentAmbiguousMatch(bool ambiguous_match) {
+  base::UmaHistogramBoolean("TextFragmentAnchor.AmbiguousMatch",
+                            ambiguous_match);
+}
+
+void LogTextFragmentLinkOpenSource(const GURL& referrer) {
+  base::UmaHistogramEnumeration("TextFragmentAnchor.LinkOpenSource",
+                                GetLinkSource(referrer));
+}
+
+void LogTextFragmentMatchRate(int matches, int text_fragments) {
+  if (text_fragments == 0) {
+    NOTREACHED();
+    return;
+  }
+
+  const int match_rate_percent =
+      static_cast<int>(100 * ((matches + 0.0) / text_fragments));
+  base::UmaHistogramPercentage("TextFragmentAnchor.MatchRate",
+                               match_rate_percent);
+}
+
+void LogTextFragmentSelectorCount(int count) {
+  base::UmaHistogramCounts100("TextFragmentAnchor.SelectorCount", count);
+}
+
+}  // namespace shared_highlighting

components/shared_highlighting/core/common/shared_highlighting_metrics.h

@@ -5,10 +5,12 @@
 #ifndef COMPONENTS_SHARED_HIGHLIGHTING_CORE_COMMON_SHARED_HIGHLIGHTING_METRICS_H_
 #define COMPONENTS_SHARED_HIGHLIGHTING_CORE_COMMON_SHARED_HIGHLIGHTING_METRICS_H_
 
+#include "url/gurl.h"
+
 namespace shared_highlighting {
 
 // Update corresponding |LinkGenerationError| in enums.xml.
-enum LinkGenerationError {
+enum class LinkGenerationError {
   kIncorrectSelector,
   kNoRange,
   kNoContext,
@@ -16,8 +18,33 @@ enum LinkGenerationError {
   kContextLimitReached,
   kEmptySelection,
 
-  kMaxValue = kContextLimitReached
+  kMaxValue = kEmptySelection,
 };
+
+// Update corresponding |TextFragmentLinkOpenSource| in enums.xml.
+enum class TextFragmentLinkOpenSource {
+  kUnknown,
+  kSearchEngine,
+
+  kMaxValue = kSearchEngine,
+};
+
+// Records whether an individual text fragment could not be scrolled to because
+// there was an |ambiguous_match| (generally because more than one matching
+// passage was found).
+void LogTextFragmentAmbiguousMatch(bool ambiguous_match);
+
+// Records the source of the text fragment based on its |referrer|. E.g. a
+// search engine.
+void LogTextFragmentLinkOpenSource(const GURL& referrer);
+
+// Records the success rate, which is the number of |matches| over number of
+// |text_fragments| in the url param.
+void LogTextFragmentMatchRate(int matches, int text_fragments);
+
+// Records the total |count| of text fragment selectors in the URL param.
+void LogTextFragmentSelectorCount(int count);
+
 }  // namespace shared_highlighting
 
 #endif  // COMPONENTS_SHARED_HIGHLIGHTING_CORE_COMMON_SHARED_HIGHLIGHTING_METRICS_H_
\ No newline at end of file

components/shared_highlighting/core/common/shared_highlighting_metrics_unittest.cc

+// Copyright 2020 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/shared_highlighting/core/common/shared_highlighting_metrics.h"
+
+#include "base/test/metrics/histogram_tester.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "url/gurl.h"
+
+namespace shared_highlighting {
+
+namespace {
+
+TEST(SharedHighlightingMetricsTest, LogTextFragmentAmbiguousMatch) {
+  base::HistogramTester histogram_tester;
+
+  LogTextFragmentAmbiguousMatch(true);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.AmbiguousMatch", 1, 1);
+
+  LogTextFragmentAmbiguousMatch(false);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.AmbiguousMatch", 0, 1);
+  histogram_tester.ExpectTotalCount("TextFragmentAnchor.AmbiguousMatch", 2);
+}
+
+TEST(SharedHighlightingMetricsTest, LogTextFragmentLinkOpenSource) {
+  base::HistogramTester histogram_tester;
+
+  GURL search_engine_url = GURL("https://google.com");
+  GURL non_search_engine_url = GURL("https://example.com");
+
+  LogTextFragmentLinkOpenSource(search_engine_url);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.LinkOpenSource", 1, 1);
+
+  LogTextFragmentLinkOpenSource(non_search_engine_url);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.LinkOpenSource", 0, 1);
+  histogram_tester.ExpectTotalCount("TextFragmentAnchor.LinkOpenSource", 2);
+}
+
+TEST(SharedHighlightingMetricsTest, LogTextFragmentMatchRate) {
+  base::HistogramTester histogram_tester;
+
+  LogTextFragmentMatchRate(/*matches=*/2, /*nb_selectors=*/2);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.MatchRate", 100, 1);
+
+  LogTextFragmentMatchRate(/*matches=*/1, /*nb_selectors=*/2);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.MatchRate", 50, 1);
+  histogram_tester.ExpectTotalCount("TextFragmentAnchor.MatchRate", 2);
+}
+
+TEST(SharedHighlightingMetricsTest, LogTextFragmentSelectorCount) {
+  base::HistogramTester histogram_tester;
+
+  LogTextFragmentSelectorCount(1);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.SelectorCount", 1, 1);
+
+  LogTextFragmentSelectorCount(20);
+  histogram_tester.ExpectBucketCount("TextFragmentAnchor.SelectorCount", 20, 1);
+  histogram_tester.ExpectTotalCount("TextFragmentAnchor.SelectorCount", 2);
+}
+
+}  // namespace
+
+}  // namespace shared_highlighting

tools/metrics/histograms/histograms_xml/others/histograms.xml

@@ -14506,9 +14506,18 @@ should be kept until we remove incident reporting. -->
   <owner>gayane@chromium.org</owner>
   <owner>chrome-shared-highlighting@google.com</owner>
   <summary>
-    Recorded for every navigatin to a link with a valid text fragment selector
+    Recorded for every navigation to a link with a valid text fragment selector
     (e.g. #:=:text=SELECTOR). Indicates source type that navigation originated
-    from.
+    from. It only know about search engines that come from the pre-populated
+    list installed with Chrome. If the user uses a search engine not on the
+    list, it won't count as a search engine. This is even true if the user have
+    a custom search engine. These custom search engines can be created by hand
+    or auto-generated. In either case, it's not going to count as a search
+    engine. Also, it only checks to see if the *referrer* is from a domain
+    associated with search engine. If someone posts a link somewhere on a web
+    site that happens to have a search engine known to Google and that links
+    includes the fragment tokens, then if a user clicks that link, it'll look
+    like it came from a search engine even thought they did not.
   </summary>
 </histogram>