Fix to Google CAPTCHA UMA collection to avoid double-counting solutions.

In some cases, a CAPTCHA solution will itself redirect (e.g., from
http:// to https://). This CL fixes the double-counting problem.

BUG=560470

Review URL: https://codereview.chromium.org/1465313003

Cr-Commit-Position: refs/heads/master@{#362156}

chrome/browser/page_load_metrics/observers/google_captcha_observer.cc

@@ -43,18 +43,22 @@ bool IsGoogleCaptcha(const GURL& url) {
 
 GoogleCaptchaObserver::GoogleCaptchaObserver(
     page_load_metrics::PageLoadMetricsObservable* metrics)
- : metrics_(metrics) {}
+    : saw_solution_(false), metrics_(metrics) {}
 
 void GoogleCaptchaObserver::OnCommit(
     content::NavigationHandle* navigation_handle) {
   if (IsGoogleCaptcha(navigation_handle->GetURL()))
     RecordGoogleCaptchaEvent(GOOGLE_CAPTCHA_SHOWN);
+  if (saw_solution_) {
+    RecordGoogleCaptchaEvent(GOOGLE_CAPTCHA_SOLVED);
+    saw_solution_ = false;
+  }
 }
 
 void GoogleCaptchaObserver::OnRedirect(
     content::NavigationHandle* navigation_handle) {
   if (IsGoogleCaptcha(navigation_handle->GetReferrer().url))
-    RecordGoogleCaptchaEvent(GOOGLE_CAPTCHA_SOLVED);
+    saw_solution_ = true;
 }
 
 void GoogleCaptchaObserver::OnPageLoadMetricsGoingAway() {

chrome/browser/page_load_metrics/observers/google_captcha_observer.h

@@ -25,6 +25,7 @@ class GoogleCaptchaObserver
   void OnPageLoadMetricsGoingAway() override;
 
  private:
+  bool saw_solution_;
   page_load_metrics::PageLoadMetricsObservable* const metrics_;
   DISALLOW_COPY_AND_ASSIGN(GoogleCaptchaObserver);