Add UMA to count the number of Google CAPTCHA pages shown and solved by users.

chrome/browser/page_load_metrics/observers/google_captcha_observer.cc

Index: chrome/browser/page_load_metrics/observers/google_captcha_observer.cc
diff --git a/chrome/browser/page_load_metrics/observers/google_captcha_observer.cc b/chrome/browser/page_load_metrics/observers/google_captcha_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..dd746a6d4c6d0f5f7a6b5683e5b81b8a85580438
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+++ b/chrome/browser/page_load_metrics/observers/google_captcha_observer.cc
@@ -0,0 +1,65 @@
+// 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 "chrome/browser/page_load_metrics/observers/google_captcha_observer.h"
+
+#include "base/metrics/histogram.h"
+#include "base/strings/string_util.h"
+#include "components/page_load_metrics/browser/page_load_metrics_macros.h"
+#include "components/page_load_metrics/common/page_load_timing.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+
+namespace google_captcha_observer {
+
+namespace {
+
+const char kGoogleCaptchaEvents[] = "PageLoad.Clients.GoogleCaptcha.Events";
+
+enum GoogleCaptchaEvent {
+  // A Google CAPTCHA page was shown to the user.
+  GOOGLE_CAPTCHA_SHOWN,
+  // A Google CAPTCHA page was solved by the user.
+  GOOGLE_CAPTCHA_SOLVED,
+  // Add new values before this final count.
+  GOOGLE_CAPTCHA_EVENT_BOUNDARY,
+};
+
+void RecordGoogleCaptchaEvent(GoogleCaptchaEvent event) {
+  UMA_HISTOGRAM_ENUMERATION(
+      kGoogleCaptchaEvents, event,
+      GOOGLE_CAPTCHA_EVENT_BOUNDARY);
+}
+
+}  // namespace
+
+bool IsGoogleCaptcha(const GURL& url) {
+  return (base::StartsWith(url.host(), "ipv4.google.",
+                           base::CompareCase::SENSITIVE)
+          || base::StartsWith(url.host(), "ipv6.google.",
+                              base::CompareCase::SENSITIVE))
+      && base::StartsWith(url.path(), "/sorry", base::CompareCase::SENSITIVE);
+}
+
+GoogleCaptchaObserver::GoogleCaptchaObserver(
+    page_load_metrics::PageLoadMetricsObservable* metrics)
+ : metrics_(metrics) {}
+
+void GoogleCaptchaObserver::OnCommit(
+    content::NavigationHandle* navigation_handle) {
+  if (IsGoogleCaptcha(navigation_handle->GetURL()))
+    RecordGoogleCaptchaEvent(GOOGLE_CAPTCHA_SHOWN);
+}
+
+void GoogleCaptchaObserver::OnRedirect(
+    content::NavigationHandle* navigation_handle) {
+  if (IsGoogleCaptcha(navigation_handle->GetReferrer().url))
+    RecordGoogleCaptchaEvent(GOOGLE_CAPTCHA_SOLVED);
+}
+
+void GoogleCaptchaObserver::OnPageLoadMetricsGoingAway() {
+  metrics_->RemoveObserver(this);
+  delete this;
+}
+
+}  // namespace google_captcha_observer