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

components/page_load_metrics/browser/metrics_web_contents_observer.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 "components/page_load_metrics/browser/metrics_web_contents_observer.h"
 
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
+#include "base/metrics/user_metrics.h"
 #include "components/page_load_metrics/browser/page_load_metrics_macros.h"
 #include "components/page_load_metrics/common/page_load_metrics_messages.h"
 #include "components/page_load_metrics/common/page_load_timing.h"
 #include "components/rappor/rappor_service.h"
 #include "components/rappor/rappor_utils.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
@@ skipping 132 matching lines @@
   url_ = navigation_handle->GetURL();
   // We log the event that this load started. Because we don't know if a load is
   // relevant or if it will commit before now, we have to log this event at
   // commit time.
   RecordCommittedEvent(COMMITTED_LOAD_STARTED, !started_in_foreground_);
 
   FOR_EACH_OBSERVER(PageLoadMetricsObserver, *observers_,
                     OnCommit(navigation_handle));
 }
 
+void PageLoadTracker::Redirect(content::NavigationHandle* navigation_handle) {
+  FOR_EACH_OBSERVER(PageLoadMetricsObserver, *observers_,
+                    OnRedirect(navigation_handle));
+}
+
 bool PageLoadTracker::UpdateTiming(const PageLoadTiming& new_timing) {
   // Throw away IPCs that are not relevant to the current navigation.
   // Two timing structures cannot refer to the same navigation if they indicate
   // that a navigation started at different times, so a new timing struct with a
   // different start time from an earlier struct is considered invalid.
   bool valid_timing_descendent =
       timing_.navigation_start.is_null() ||
       timing_.navigation_start == new_timing.navigation_start;
   if (IsValidPageLoadTiming(new_timing) && valid_timing_descendent) {
     timing_ = new_timing;
@@ skipping 292 matching lines @@
   const std::string& mime_type = web_contents()->GetContentsMimeType();
   DCHECK(!browser_url.is_empty());
   DCHECK(!mime_type.empty());
   if (!IsRelevantNavigation(navigation_handle, browser_url, mime_type))
     return;
 
   committed_load_ = finished_nav.Pass();
   committed_load_->Commit(navigation_handle);
 }
 
+void MetricsWebContentsObserver::DidRedirectNavigation(
+    content::NavigationHandle* navigation_handle) {
+  if (!navigation_handle->IsInMainFrame())
+    return;
+  auto it = provisional_loads_.find(navigation_handle);
+  if (it == provisional_loads_.end())
+    return;
+  it->second->Redirect(navigation_handle);
+}
+
 void MetricsWebContentsObserver::WasShown() {
   in_foreground_ = true;
   if (committed_load_)
     committed_load_->WebContentsShown();
   for (const auto& kv : provisional_loads_) {
     kv.second->WebContentsShown();
   }
 }
 
 void MetricsWebContentsObserver::WasHidden() {
@@ skipping 42 matching lines @@
 
   if (!committed_load_->UpdateTiming(timing)) {
     // If the page load tracker cannot update its timing, something is wrong
     // with the IPC (it's from another load, or it's invalid in some other way).
     // We expect this to be a rare occurrence.
     RecordInternalError(ERR_BAD_TIMING_IPC);
   }
 }
 
 }  // namespace page_load_metrics