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

chrome/browser/extensions/extension_functional_browsertest.cc

 // Copyright (c) 2012 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 <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"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/test_utils.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
 #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 {
 
 class ExtensionFunctionalTest : public ExtensionBrowserTest {
  public:
   void InstallExtensionSilently(ExtensionService* service,
                                 const char* filename) {
     ExtensionRegistry* registry = ExtensionRegistry::Get(profile());
     size_t num_before = registry->enabled_extensions().size();
 
@@ skipping 71 matching lines @@
   EXPECT_TRUE(util::IsIncognitoEnabled(last_loaded_extension_id(), profile()));
 
   // Disallow extension in incognito mode and verify.
   service->EnableExtension(last_loaded_extension_id());
   util::SetIsIncognitoEnabled(last_loaded_extension_id(), profile(), false);
   EXPECT_FALSE(util::IsIncognitoEnabled(last_loaded_extension_id(), profile()));
 }
 
 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"));
   ASSERT_TRUE(extension);
   GURL extension_url = extension->GetResourceURL("file.html");
 
   // Load the extension in two unrelated tabs.
   ui_test_utils::NavigateToURL(browser(), extension_url);
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), extension_url, WindowOpenDisposition::NEW_FOREGROUND_TAB,
@@ skipping 32 matching lines @@
 
   // Verify that |tab1_popup| can find unrelated frames from the same extension
   // (i.e. that it can find |tab2|.
   std::string location_of_opened_window;
   EXPECT_TRUE(ExecuteScriptAndExtractString(
       tab1_popup,
       "var w = window.open('', 'tab2');\n"
       "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