[DRAFT] Allow a user to revert to their previous theme without closing infobar

chrome/browser/ui/search/instant_extended_interactive_uitest.cc

 // Copyright 2013 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 <sstream>
 
 #include "base/command_line.h"
 #include "base/metrics/histogram_base.h"
 #include "base/metrics/histogram_samples.h"
 #include "base/metrics/statistics_recorder.h"
@@ skipping 294 matching lines @@
     InstantTestBase::Init(instant_url);
   }
 
   void InstallThemeSource() {
     ThemeSource* theme = new ThemeSource(profile());
     content::URLDataSource::Add(profile(), theme);
   }
 
   void InstallThemeAndVerify(const std::string& theme_dir,
                              const std::string& theme_name) {
-    const base::FilePath theme_path = test_data_dir_.AppendASCII(theme_dir);
-    ASSERT_TRUE(InstallExtensionWithUIAutoConfirm(
-        theme_path, 1, ExtensionBrowserTest::browser()));
     const extensions::Extension* theme =
         ThemeServiceFactory::GetThemeForProfile(
             ExtensionBrowserTest::browser()->profile());
-    ASSERT_NE(static_cast<extensions::Extension*>(NULL), theme);
-    ASSERT_EQ(theme->name(), theme_name);
+    // If there is already a theme installed, the current theme should be
+    // disabled and the new one installed + enabled.
+    int expected_change = theme ? 0 : 1;
+
+    const base::FilePath theme_path = test_data_dir_.AppendASCII(theme_dir);
+    ASSERT_TRUE(InstallExtensionWithUIAutoConfirm(
+        theme_path, expected_change, ExtensionBrowserTest::browser()));
+    const extensions::Extension* new_theme =
+        ThemeServiceFactory::GetThemeForProfile(
+            ExtensionBrowserTest::browser()->profile());
+    ASSERT_NE(static_cast<extensions::Extension*>(NULL), new_theme);
+    ASSERT_EQ(new_theme->name(), theme_name);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InstantPolicyTest);
 };
 
 #if defined(HTML_INSTANT_EXTENDED_POPUP)
 
 IN_PROC_BROWSER_TEST_F(InstantExtendedTest, ExtendedModeIsOn) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant(browser()));
@@ skipping 1311 matching lines @@
   content::WindowedNotificationObserver observer(
       content::NOTIFICATION_LOAD_STOP,
       content::Source<content::NavigationController>(
           &ntp_contents->GetController()));
   service->SetDefaultSearchProvider(template_url);
   observer.Wait();
 
   // Make sure the URL remains the same.
   EXPECT_EQ(ntp_url, ntp_contents->GetURL());
 }