NOT YET READY: UMA recording the kind of target frame when extensions pierce browsing instance.

chrome/browser/extensions/extension_functional_browsertest.cc

Index: chrome/browser/extensions/extension_functional_browsertest.cc
diff --git a/chrome/browser/extensions/extension_functional_browsertest.cc b/chrome/browser/extensions/extension_functional_browsertest.cc
index 9e6b5ba6cd418e91294e17282ff20128af44beba..f70bb33f97b82a8581f1927af1f14bd1a3180f61 100644
--- a/chrome/browser/extensions/extension_functional_browsertest.cc
+++ b/chrome/browser/extensions/extension_functional_browsertest.cc
@@ -4,6 +4,7 @@
 
 #include <stddef.h>
 
+#include "base/test/histogram_tester.h"
 #include "build/build_config.h"
 #include "chrome/browser/extensions/crx_installer.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
@@ -23,6 +24,8 @@
 #include "extensions/browser/extension_util.h"
 #include "extensions/browser/notification_types.h"
 #include "extensions/browser/test_extension_registry_observer.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
 
 namespace extensions {
 
@@ -114,6 +117,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionFunctionalTest, MAYBE_TestSetExtensionsState) {
 
 IN_PROC_BROWSER_TEST_F(ExtensionFunctionalTest,
                        FindingUnrelatedExtensionFramesFromAboutBlank) {
+  base::HistogramTester histogram_tester;
+
   // Load an extension before adding tabs.
   const extensions::Extension* extension =
       LoadExtension(test_data_dir_.AppendASCII("simple_with_file"));
@@ -166,6 +171,16 @@ IN_PROC_BROWSER_TEST_F(ExtensionFunctionalTest,
       "window.domAutomationController.send(w.location.href);",
       &location_of_opened_window));
   EXPECT_EQ(tab2->GetLastCommittedURL(), location_of_opened_window);
+
+  // Verify UMA got recorded as expected.
+  // DO NOT SUBMIT - need to flush/sync the histograms logged in the renderer
+  // for |tab1_popup|.

[Łukasz Anforowicz, 2017/06/07 23:24:35]

How would a browser test force a sync in a canonical way?  I guess I can try
closing all the tabs or something like that, but maybe there is a better, more
direct way of syncing the data?

FWIW, right now the new verification below fails (GetAllSamples returns an empty
vector), despite the fact that I clearly see (via LOG(ERROR) added in
extension_frame_helper.cc) that the new UMA are getting recorder.

+  EXPECT_THAT(histogram_tester.GetAllSamples(
+                  "Extensions.BrowsingInstanceViolation.ExtensionType"),
+              testing::ElementsAre(base::Bucket(Manifest::TYPE_EXTENSION, 1)));
+  EXPECT_THAT(histogram_tester.GetAllSamples(
+                  "Extensions.BrowsingInstanceViolation.ExtensionViewType"),
+              testing::ElementsAre(base::Bucket(VIEW_TYPE_TAB_CONTENTS, 1)));
 }
 
 }  // namespace extensions