Implement signin using webview

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index f57d75c04f098c77d5fe3bdf545caba967341b31..2baf02163f65dbe717858272d534cde6a0a83889 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -712,7 +712,8 @@ std::string ChromeContentBrowserClient::GetStoragePartitionIdForSite(
   // SiteInstance URL - "chrome-guest://app_id/persist?partition".
   if (site.SchemeIs(content::kGuestScheme)) {
     partition_id = site.spec();
-  } else if (site.GetOrigin().spec() == kChromeUIChromeSigninURL) {
+  } else if (site.GetOrigin().spec() == kChromeUIChromeSigninURL &&
+            !switches::IsEnableWebviewBasedSignin()) {
     // Chrome signin page has an embedded iframe of extension and web content,
     // thus it must be isolated from other webUI pages.
     partition_id = site.GetOrigin().spec();
@@ -776,7 +777,8 @@ void ChromeContentBrowserClient::GetStoragePartitionConfigForSite(
   }
 #endif
 
-  if (!success && (site.GetOrigin().spec() == kChromeUIChromeSigninURL)) {
+  if (!success && (site.GetOrigin().spec() == kChromeUIChromeSigninURL) &&
+      !switches::IsEnableWebviewBasedSignin()) {
     // Chrome signin page has an embedded iframe of extension and web content,
     // thus it must be isolated from other webUI pages.
     *partition_domain = chrome::kChromeUIChromeSigninHost;