Revert "content: convert accessibility notifications to callbacks"

content/browser/accessibility/dump_accessibility_tree_browsertest.cc

Index: content/browser/accessibility/dump_accessibility_tree_browsertest.cc
diff --git a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
index b1c7d98d1357d83f57706fb40f70631bd1e70472..9b47dfb408bcbcd55aa88a43bd3ef8bb01f57a67 100644
--- a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
+++ b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
@@ -18,6 +18,8 @@
 #include "content/browser/accessibility/dump_accessibility_tree_helper.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/port/browser/render_widget_host_view_port.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_types.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/test/test_utils.h"
@@ -26,16 +28,14 @@
 #include "content/shell/shell.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-namespace content {
-
 namespace {
+  static const char kCommentToken = '#';
+  static const char* kMarkSkipFile = "#<skip";
+  static const char* kMarkEndOfFile = "<-- End-of-file -->";
+  static const char* kSignalDiff = "*";
+} // namespace
 
-const char kCommentToken = '#';
-const char kMarkSkipFile[] = "#<skip";
-const char kMarkEndOfFile[] = "<-- End-of-file -->";
-const char kSignalDiff[] = "*";
-
-}  // namespace
+namespace content {
 
 typedef DumpAccessibilityTreeHelper::Filter Filter;
 
@@ -166,17 +166,17 @@ void DumpAccessibilityTreeTest::RunTest(
   }
 
   // Load the page.
+  WindowedNotificationObserver tree_updated_observer(
+      NOTIFICATION_ACCESSIBILITY_LOAD_COMPLETE,
+      NotificationService::AllSources());
   string16 html_contents16;
   html_contents16 = UTF8ToUTF16(html_contents);
   GURL url = GetTestUrl("accessibility",
                         html_file.BaseName().MaybeAsASCII().c_str());
-  scoped_refptr<MessageLoopRunner> loop_runner(new MessageLoopRunner);
-  view_host->SetAccessibilityLoadCompleteCallbackForTesting(
-      loop_runner->QuitClosure());
   NavigateToURL(shell(), url);
 
   // Wait for the tree.
-  loop_runner->Run();
+  tree_updated_observer.Wait();
 
   // Perform a diff (or write the initial baseline).
   string16 actual_contents_utf16;