Fix sizing issues in the tab modal signin flow.

chrome/browser/ui/signin_view_controller_delegate.cc

 // Copyright 2016 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 "chrome/browser/ui/signin_view_controller_delegate.h"
 
 #include "base/bind.h"
+#include "base/values.h"
 #include "chrome/browser/ui/signin_view_controller.h"
 #include "chrome/browser/ui/webui/signin/get_auth_frame.h"
 #include "content/public/browser/web_contents.h"
 
 namespace {
 
 content::WebContents* GetAuthFrameWebContents(
     content::WebContents* web_ui_web_contents) {
   return signin::GetAuthFrameWebContents(web_ui_web_contents, "signin-frame");
 }
 
 }  // namespace
 
 SigninViewControllerDelegate::SigninViewControllerDelegate(
     SigninViewController* signin_view_controller,
     content::WebContents* web_contents)
     : signin_view_controller_(signin_view_controller),
       web_contents_(web_contents) {
   web_contents_->SetDelegate(this);
-  web_contents_->GetWebUI()->RegisterMessageCallback(
-      "navigationButtonClicked",
-      base::Bind(&SigninViewControllerDelegate::HandleNavigationButtonClicked,
-                 base::Unretained(this)));
 }
 
 SigninViewControllerDelegate::~SigninViewControllerDelegate() {}
 
 void SigninViewControllerDelegate::CloseModalSignin() {
   ResetSigninViewControllerDelegate();
   PerformClose();
 }
 
 void SigninViewControllerDelegate::ResetSigninViewControllerDelegate() {
@@ skipping 12 matching lines @@
 // content::WebContentsDelegate
 void SigninViewControllerDelegate::LoadingStateChanged(
     content::WebContents* source,
     bool to_different_document) {
   if (CanGoBack(source))
     source->GetWebUI()->CallJavascriptFunction("inline.login.showBackButton");
   else
     source->GetWebUI()->CallJavascriptFunction("inline.login.showCloseButton");
 }
 
-void SigninViewControllerDelegate::HandleNavigationButtonClicked(
-    const base::ListValue* args) {
+void SigninViewControllerDelegate::PerformNavigation() {
   if (CanGoBack(web_contents_)) {
     auto auth_web_contents = GetAuthFrameWebContents(web_contents_);
     auth_web_contents->GetController().GoBack();
   } else {
     CloseModalSignin();
   }
 }