Reimplement inline signin with iframe

chrome/browser/ui/webui/signin/inline_login_ui.cc

Index: chrome/browser/ui/webui/signin/inline_login_ui.cc
diff --git a/chrome/browser/ui/webui/signin/inline_login_ui.cc b/chrome/browser/ui/webui/signin/inline_login_ui.cc
index 4748c0418a079a73404adc0502c37a5927b072bf..62492b33824a59502100216cd427859880702f6a 100644
--- a/chrome/browser/ui/webui/signin/inline_login_ui.cc
+++ b/chrome/browser/ui/webui/signin/inline_login_ui.cc
@@ -22,6 +22,7 @@ namespace {
 content::WebUIDataSource* CreateWebUIDataSource() {
   content::WebUIDataSource* source =
         content::WebUIDataSource::Create(chrome::kChromeUIChromeSigninHost);
+  source->DisableContentSecurityPolicy(); // So we can use iframe.

[xiyuan, 2014/01/26 01:59:57]

nit: Could we use OverrideContentSecurityPolicyFrameSrc instead of disabling all
CSP?
e.g.
source->OverrideContentSecurityPolicyFrameSrc("frame-src chrome-extension:;");

[guohui, 2014/01/29 12:50:51]

Done.

   source->SetUseJsonJSFormatV2();
   source->SetJsonPath("strings.js");
 
@@ -45,10 +46,6 @@ InlineLoginUI::InlineLoginUI(content::WebUI* web_ui)
   web_ui->AddMessageHandler(new chromeos::InlineLoginHandlerChromeOS());
 #else
   web_ui->AddMessageHandler(new InlineLoginHandlerImpl());
-  // Required for intercepting extension function calls when the page is loaded
-  // in a bubble (not a full tab, thus tab helpers are not registered
-  // automatically).
-  extensions::TabHelper::CreateForWebContents(web_ui->GetWebContents());
 #endif
 }