Fix sizing issues in the tab modal signin flow.

chrome/browser/ui/views/profiles/signin_view_controller_delegate_views.h

Index: chrome/browser/ui/views/profiles/signin_view_controller_delegate_views.h
diff --git a/chrome/browser/ui/views/profiles/signin_view_controller_delegate_views.h b/chrome/browser/ui/views/profiles/signin_view_controller_delegate_views.h
index b36c3d93efde785b11fb7e61482c5589a24aa3b0..277cf77552021bb42d5720d1fd3868bb1f5b40dd 100644
--- a/chrome/browser/ui/views/profiles/signin_view_controller_delegate_views.h
+++ b/chrome/browser/ui/views/profiles/signin_view_controller_delegate_views.h
@@ -32,10 +32,14 @@ class WebView;
 class SigninViewControllerDelegateViews : public views::DialogDelegateView,
                                           public SigninViewControllerDelegate {
  public:
+  // Creates and displays a constrained window containing |web_contents|. If
+  // |wait_for_size| is true, the delegate will wait for ResizeNativeView() to
+  // be called by the base class before displaying the constrained window.
   SigninViewControllerDelegateViews(
       SigninViewController* signin_view_controller,
       views::WebView* content_view,
-      Browser* browser);
+      Browser* browser,
+      bool wait_for_size);
 
   // Creates the web view that contains the signin flow in |mode| using
   // |profile| as the web content's profile, then sets |delegate| as the created
@@ -59,12 +63,21 @@ class SigninViewControllerDelegateViews : public views::DialogDelegateView,
 
  private:
   void PerformClose() override;
+  void ResizeNativeView(int height) override;
+
+  void DisplayModal();
 
   ~SigninViewControllerDelegateViews() override;
 
   views::WebView* content_view_;
   views::Widget* modal_signin_widget_;  // Not owned.
 
+  // wait_for_size_ stores whether the dialog should only be shown after its
+  // content's size has been laid out and measured so that the constrained
+  // window is sized to the content.
+  bool wait_for_size_;
+  Browser* browser_;
+
   DISALLOW_COPY_AND_ASSIGN(SigninViewControllerDelegateViews);
 };