Make WebUI webview content script work with incognito.

chrome/browser/ui/webui/webui_webview_browsertest.cc

Index: chrome/browser/ui/webui/webui_webview_browsertest.cc
diff --git a/chrome/browser/ui/webui/webui_webview_browsertest.cc b/chrome/browser/ui/webui/webui_webview_browsertest.cc
index 6c3ed9c8cfcaba3787a706d88cad7b4f43af6b81..6fea4921ea0d7732bafe7b7d5803d0ea5fbab4af 100644
--- a/chrome/browser/ui/webui/webui_webview_browsertest.cc
+++ b/chrome/browser/ui/webui/webui_webview_browsertest.cc
@@ -4,6 +4,8 @@
 
 #include "base/macros.h"
 #include "base/path_service.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/ui_test_utils.h"
@@ -131,3 +133,17 @@ IN_PROC_BROWSER_TEST_F(WebUIWebViewBrowserTest, AddContentScriptWithCode) {
       "testAddContentScriptWithCode",
       new base::StringValue(GetTestUrl("empty.html").spec())));
 }
+
+#if defined(OS_CHROMEOS)
+IN_PROC_BROWSER_TEST_F(WebUIWebViewBrowserTest, AddContentScriptIncognito) {

[Devlin, 2015/04/27 17:55:56]

Awesome.

Can you:
- Put a comment saying that, right now, we only have incognito WebUI on CrOS,
but that this should theoretically work for all platforms
- Check that this did indeed fail before this patch?

[Xi Han, 2015/04/27 18:17:48]

Added. Yes, I modified other tests, which are in incognito mode and navigate to
other url like chrome://about/, and let them navigate to chrome://chrome-signin,
they do failed.

+  Browser* incognito_browser = ui_test_utils::OpenURLOffTheRecord(
+      browser()->profile(), GetWebViewEnabledWebUIURL());
+
+  SetWebUIInstance(
+      incognito_browser->tab_strip_model()->GetActiveWebContents()->GetWebUI());
+
+  ASSERT_TRUE(WebUIBrowserTest::RunJavascriptAsyncTest(
+      "testAddContentScript",
+      new base::StringValue(GetTestUrl("empty.html").spec())));
+}
+#endif