[MD settings] test UMA when changing site settings exceptions

chrome/browser/ui/webui/settings/site_settings_handler_unittest.cc

Index: chrome/browser/ui/webui/settings/site_settings_handler_unittest.cc
diff --git a/chrome/browser/ui/webui/settings/site_settings_handler_unittest.cc b/chrome/browser/ui/webui/settings/site_settings_handler_unittest.cc
index a156676b83198c9e00233335f38ea5105fe7438f..3b869a210f4eb81ea37053c7797b2afe43a2abd6 100644
--- a/chrome/browser/ui/webui/settings/site_settings_handler_unittest.cc
+++ b/chrome/browser/ui/webui/settings/site_settings_handler_unittest.cc
@@ -6,6 +6,7 @@
 
 #include <memory>
 
+#include "base/test/histogram_tester.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/ui/webui/site_settings_helper.h"
 #include "chrome/test/base/testing_profile.h"
@@ -260,8 +261,14 @@ TEST_F(SiteSettingsHandlerTest, Origins) {
   setArgs.AppendString("notifications");
   setArgs.AppendString("block");
   setArgs.AppendBoolean(false);  // Incognito.
+  base::HistogramTester histograms;
   handler()->HandleSetCategoryPermissionForOrigin(&setArgs);
   EXPECT_EQ(1U, web_ui()->call_data().size());
+  const std::string kUmaBase("WebsiteSettings.Menu.PermissionChanged");
+  histograms.ExpectTotalCount(kUmaBase, 1);
+  histograms.ExpectTotalCount(kUmaBase + ".Allowed", 0);
+  histograms.ExpectTotalCount(kUmaBase + ".Blocked", 1);
+  histograms.ExpectTotalCount(kUmaBase + ".Reset", 0);
 
   // Verify the change was successful.
   base::ListValue listArgs;
@@ -278,6 +285,10 @@ TEST_F(SiteSettingsHandlerTest, Origins) {
   resetArgs.AppendBoolean(false);  // Incognito.
   handler()->HandleResetCategoryPermissionForOrigin(&resetArgs);
   EXPECT_EQ(3U, web_ui()->call_data().size());
+  histograms.ExpectTotalCount(kUmaBase, 2);  // Including the "block" above.

[Dan Beam, 2017/05/05 01:40:48]

nit: you could just make a new scope

{
  base::HistogramTester histograms;
  histograms.ExpectTotalCount(...);
}

...

{
  base::HistogramTester histograms;
  histograms.ExpectTotalCount(...);
}

[dschuyler, 2017/05/05 21:21:35]

Done.

+  histograms.ExpectTotalCount(kUmaBase + ".Allowed", 0);
+  histograms.ExpectTotalCount(kUmaBase + ".Blocked", 1);
+  histograms.ExpectTotalCount(kUmaBase + ".Reset", 1);
 
   // Verify the reset was successful.
   handler()->HandleGetExceptionList(&listArgs);