Only report PasswordState in Sync for UMA+non-custom passphrase users.

chrome/browser/metrics/chrome_metrics_service_accessor.cc

 // Copyright 2014 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/metrics/chrome_metrics_service_accessor.h"
 
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/features.h"
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_service.h"
 #include "content/public/browser/browser_thread.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #endif
 
+namespace {
+
+const bool* gMetricsAndCrashReportingForTesting = nullptr;

[Alexei Svitkine (slow), 2016/09/02 18:05:45]

Nit: Incorrect naming convention.

We only use kFooBar for constants. Everything else should be hacker_style - so
g_metrics_and_...

I'd actually name it:

g_metrics_consent_for_testing

[Nathan Parker, 2016/09/02 22:42:36]

Done.

+
+}  // namespace
+
+// static
+void ChromeMetricsServiceAccessor::SetMetricsAndCrashReportingForTesting(
+    const bool* value) {
+  DCHECK_NE(gMetricsAndCrashReportingForTesting == nullptr, value == nullptr)
+      << "Unpaired set/reset";
+
+  gMetricsAndCrashReportingForTesting = value;
+}
+
 // static
 bool ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled() {
+  if (gMetricsAndCrashReportingForTesting)
+    return *gMetricsAndCrashReportingForTesting;
+
   // TODO(blundell): Fix the unittests that don't set up the UI thread and
   // change this to just be DCHECK_CURRENTLY_ON().
   DCHECK(
       !content::BrowserThread::IsMessageLoopValid(content::BrowserThread::UI) ||
       content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
   // This is only possible during unit tests. If the unit test didn't set the
   // local_state then it doesn't care about pref value and therefore we return
   // false.
   if (!g_browser_process->local_state()) {
@@ skipping 34 matching lines @@
 }
 
 // static
 bool ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrialWithNameHash(
     uint32_t trial_name_hash,
     const std::string& group_name) {
   return metrics::MetricsServiceAccessor::
       RegisterSyntheticFieldTrialWithNameHash(
           g_browser_process->metrics_service(), trial_name_hash, group_name);
 }