[Extensions] Remove LazyBackgroundObserver

LazyBackgroundObserver is a test class that provides utilities to wait
for an extension's background page to open (WaitUntilLoaded()),
close (WaitUntilClosed()), or both open and then close (Wait()).

The functionality of this class can be entirely replaced by the
ExtensionHostTestHelper:

Before:
LazyBackgroundObserver lazy_background_observer(profile())
...
lazy_background_observer.Wait();

After:
ExtensionHostTestHelper host_helper(profile());
host_helper.RestrictToType(
    mojom::ViewType::kExtensionBackgroundPage);
...
host_helper.WaitForDocumentElementAvailable();
host_helper.WaitForExtensionHostDestroyed();

This is slightly more verbose, however:
- This verbosity is actually rather useful in the test. It was not clear
  from many callsites that they were actually waiting for a full open +
  close cycle, and some did not need to wait for both events.
- This reduces the number of ExtensionHost / background waiting
  utilities we have, which is helpful (and ExtensionHostTestHelper is
  far more generally useful than LazyBackgroundObserver).

Also ensure that ExtensionHostTestHelper checks the BrowserContext of
the ExtensionHost when waiting for an event (since it might be the
on- or off-the-record pair of the one the host helper was constructed
with).

Bug: 991464
Change-Id: I7cb35846441c7ad977d6cf3111c397ff84575bb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3182756
Reviewed-by: Noel Gordon <noel@chromium.org>
Reviewed-by: David Bertoni <dbertoni@chromium.org>
Commit-Queue: David Bertoni <dbertoni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#926343}

chrome/browser/ash/file_manager/external_filesystem_apitest.cc

@@ -20,7 +20,6 @@
 #include "chrome/browser/ash/profiles/profile_helper.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_apitest.h"
-#include "chrome/browser/extensions/lazy_background_page_test_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/ash/cast_config_controller_media_router.h"
@@ -37,7 +36,8 @@
 #include "content/public/test/browser_test.h"
 #include "content/public/test/test_navigation_observer.h"
 #include "content/public/test/test_utils.h"
-#include "extensions/browser/notification_types.h"
+#include "extensions/browser/extension_host_test_helper.h"
+#include "extensions/common/mojom/view_type.mojom.h"
 #include "extensions/test/result_catcher.h"
 #include "google_apis/common/test_util.h"
 #include "storage/browser/file_system/external_mount_points.h"
@@ -339,7 +339,9 @@ class FileSystemExtensionApiTestBase : public extensions::ExtensionApiTest {
         extensions::ProcessManager::SetEventPageIdleTimeForTesting(1);
       }
 
-      LazyBackgroundObserver page_complete(profile());
+      extensions::ExtensionHostTestHelper host_helper(profile());
+      host_helper.RestrictToType(
+          extensions::mojom::ViewType::kExtensionBackgroundPage);
       const Extension* file_handler =
           LoadExtension(test_data_dir_.AppendASCII(filehandler_path));
       if (!file_handler) {
@@ -348,9 +350,9 @@ class FileSystemExtensionApiTestBase : public extensions::ExtensionApiTest {
       }
 
       if (flags & FLAGS_LAZY_FILE_HANDLER) {
-        page_complete.WaitUntilClosed();
+        host_helper.WaitForHostDestroyed();
       } else {
-        page_complete.WaitUntilLoaded();
+        host_helper.WaitForDocumentElementAvailable();
       }
     }
 

chrome/browser/extensions/api/system_indicator/system_indicator_apitest.cc

@@ -7,16 +7,17 @@
 #include "chrome/browser/extensions/api/system_indicator/system_indicator_manager.h"
 #include "chrome/browser/extensions/api/system_indicator/system_indicator_manager_factory.h"
 #include "chrome/browser/extensions/extension_apitest.h"
-#include "chrome/browser/extensions/lazy_background_page_test_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "components/version_info/channel.h"
 #include "content/public/test/browser_test.h"
 #include "extensions/browser/extension_action.h"
 #include "extensions/browser/extension_action_manager.h"
+#include "extensions/browser/extension_host_test_helper.h"
 #include "extensions/browser/process_manager.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/features/feature_channel.h"
 #include "extensions/common/manifest_test.h"
+#include "extensions/common/mojom/view_type.mojom.h"
 #include "extensions/test/result_catcher.h"
 
 namespace extensions {
@@ -39,11 +40,15 @@ class SystemIndicatorApiTest : public ExtensionApiTest {
   }
 
   const Extension* LoadExtensionAndWait(const std::string& test_name) {
-    LazyBackgroundObserver page_complete(profile());
+    ExtensionHostTestHelper host_helper(profile());
+    host_helper.RestrictToType(mojom::ViewType::kExtensionBackgroundPage);
     base::FilePath extdir = test_data_dir_.AppendASCII(test_name);
     const Extension* extension = LoadExtension(extdir);
-    if (extension)
-      page_complete.Wait();
+    if (extension) {
+      // Wait for the background page to cycle.
+      host_helper.WaitForDocumentElementAvailable();
+      host_helper.WaitForHostDestroyed();
+    }
     return extension;
   }
 

chrome/browser/extensions/extension_context_menu_browsertest.cc

@@ -17,7 +17,6 @@
 #include "build/chromeos_buildflags.h"
 #include "chrome/browser/extensions/browsertest_util.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
-#include "chrome/browser/extensions/lazy_background_page_test_util.h"
 #include "chrome/browser/extensions/menu_manager_test_observer.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/renderer_context_menu/render_view_context_menu.h"
@@ -32,12 +31,14 @@
 #include "content/public/test/browser_test.h"
 #include "content/public/test/browser_test_utils.h"
 #include "extensions/browser/extension_api_frame_id_map.h"
+#include "extensions/browser/extension_host_test_helper.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/process_manager.h"
 #include "extensions/browser/state_store.h"
 #include "extensions/browser/test_management_policy.h"
 #include "extensions/common/extension_set.h"
 #include "extensions/common/features/feature_channel.h"
+#include "extensions/common/mojom/view_type.mojom.h"
 #include "extensions/test/extension_test_message_listener.h"
 #include "extensions/test/result_catcher.h"
 #include "net/dns/mock_host_resolver.h"
@@ -927,11 +928,15 @@ IN_PROC_BROWSER_TEST_P(ExtensionContextMenuLazyTest, EventPage) {
   if (GetParam() == ContextType::kServiceWorker)
     return;
   GURL about_blank("about:blank");
-  LazyBackgroundObserver page_complete(profile());
+  extensions::ExtensionHostTestHelper host_helper(profile());
+  host_helper.RestrictToType(
+      extensions::mojom::ViewType::kExtensionBackgroundPage);
   const extensions::Extension* extension =
       LoadContextMenuExtension("event_page");
   ASSERT_TRUE(extension);
-  page_complete.Wait();
+  // Wait for the background page to cycle.
+  host_helper.WaitForDocumentElementAvailable();
+  host_helper.WaitForHostDestroyed();
 
   // Test that menu items appear while the page is unloaded.
   ASSERT_TRUE(MenuHasItemWithLabel(
@@ -940,7 +945,9 @@ IN_PROC_BROWSER_TEST_P(ExtensionContextMenuLazyTest, EventPage) {
       about_blank, GURL(), GURL(), std::string("Checkbox 1")));
 
   // Test that checked menu items retain their checkedness.
-  LazyBackgroundObserver checkbox_checked(profile());
+  extensions::ExtensionHostTestHelper checkbox_checked(profile());
+  host_helper.RestrictToType(
+      extensions::mojom::ViewType::kExtensionBackgroundPage);
   std::unique_ptr<TestRenderViewContextMenu> menu(
       TestRenderViewContextMenu::Create(GetWebContents(), about_blank, GURL(),
                                         GURL()));
@@ -954,7 +961,7 @@ IN_PROC_BROWSER_TEST_P(ExtensionContextMenuLazyTest, EventPage) {
   // Executing the checkbox also fires the onClicked event.
   ExtensionTestMessageListener listener("onClicked fired for checkbox1", false);
   menu->ExecuteCommand(command_id, 0);
-  checkbox_checked.WaitUntilClosed();
+  checkbox_checked.WaitForHostDestroyed();
 
   EXPECT_TRUE(menu->IsCommandIdChecked(command_id));
   ASSERT_TRUE(listener.WaitUntilSatisfied());