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

chrome/browser/metrics/chrome_metrics_service_accessor.cc

Index: chrome/browser/metrics/chrome_metrics_service_accessor.cc
diff --git a/chrome/browser/metrics/chrome_metrics_service_accessor.cc b/chrome/browser/metrics/chrome_metrics_service_accessor.cc
index cd8e07148a694059c084a6a839aba95713955490..191425ae0a6f26f94653585a7011d91612c57d80 100644
--- a/chrome/browser/metrics/chrome_metrics_service_accessor.cc
+++ b/chrome/browser/metrics/chrome_metrics_service_accessor.cc
@@ -15,8 +15,26 @@
 #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(