Fix and re-enable test in ExtensionDialogBoundsTest

Fixed: 1141167

Change-Id: Ib0cd134262647014ebed61d8e1f3cbba675fa673
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2512786Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827525}

chrome/browser/ui/views/extensions/extension_dialog_bounds_browsertest.cc

@@ -5,6 +5,7 @@
 #include <string>
 
 #include "base/macros.h"
+#include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/accessibility/magnification_manager.h"
 #include "chrome/browser/extensions/component_loader.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
@@ -14,6 +15,8 @@
 #include "chrome/browser/ui/views/extensions/extension_dialog.h"
 #include "chromeos/constants/chromeos_switches.h"
 #include "content/public/test/browser_test.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/browser/test_extension_registry_observer.h"
 #include "extensions/test/extension_test_message_listener.h"
 
 namespace {
@@ -38,7 +41,11 @@ class ExtensionDialogBoundsTest
   }
 
   void EnableDockedMagnifier() const {
+    extensions::TestExtensionRegistryObserver registry_observer(
+        extensions::ExtensionRegistry::Get(
+            chromeos::AccessibilityManager::Get()->profile()));
     chromeos::MagnificationManager::Get()->SetDockedMagnifierEnabled(true);
+    registry_observer.WaitForExtensionLoaded();
     ASSERT_TRUE(
         chromeos::MagnificationManager::Get()->IsDockedMagnifierEnabled());
   }
@@ -77,10 +84,7 @@ IN_PROC_BROWSER_TEST_F(ExtensionDialogBoundsTest, Test_OpenFileDialog) {
   ShowAndVerifyUi();
 }
 
-// TODO(crbug.com/1012025): Test crashes as enabling docked magnifier now loads
-// another extension (Accessibility Common).
-IN_PROC_BROWSER_TEST_F(ExtensionDialogBoundsTest,
-                       DISABLED_Test_BigExtensionDialog) {
+IN_PROC_BROWSER_TEST_F(ExtensionDialogBoundsTest, Test_BigExtensionDialog) {
   EnableDockedMagnifier();
   ShowAndVerifyUi();
 }