[cros] Use WideButton for all screens, increase textfield vmargin on login screen.

views/controls/button/text_button.h

Index: views/controls/button/text_button.h
diff --git a/views/controls/button/text_button.h b/views/controls/button/text_button.h
index fc821f4a1625fa83330bc49bfeae4214239b5f3f..b9329b4f1a0a4bdae08a0554861d155dbd2f4a17 100644
--- a/views/controls/button/text_button.h
+++ b/views/controls/button/text_button.h
@@ -138,6 +138,9 @@ class TextButton : public CustomButton {
 
   void set_max_width(int max_width) { max_width_ = max_width; }
   void SetFont(const gfx::Font& font);
+  // Return the font used by this button.
+  gfx::Font font() const { return font_; }
+
   void SetEnabledColor(SkColor color);
   void SetDisabledColor(SkColor color);
   void SetHighlightColor(SkColor color);