Factor out the layout code from OpaqueBrowserFrameView for testing.

ui/views/controls/button/image_button.cc

Index: ui/views/controls/button/image_button.cc
diff --git a/ui/views/controls/button/image_button.cc b/ui/views/controls/button/image_button.cc
index ff355ebd68ea86e4278707ed222a703dbcc6d377..f6cff61b6ecb8f0916ee873c69a54ff0860ab458 100644
--- a/ui/views/controls/button/image_button.cc
+++ b/ui/views/controls/button/image_button.cc
@@ -16,6 +16,8 @@ namespace views {
 static const int kDefaultWidth = 16;   // Default button width if no theme.
 static const int kDefaultHeight = 14;  // Default button height if no theme.
 
+const char ImageButton::kViewClassName[] = "ImageButton";
+
 ////////////////////////////////////////////////////////////////////////////////
 // ImageButton, public:
 
@@ -84,6 +86,10 @@ gfx::Size ImageButton::GetPreferredSize() {
   return size;
 }
 
+const char* ImageButton::GetClassName() const {
+  return kViewClassName;
+}
+
 void ImageButton::OnPaint(gfx::Canvas* canvas) {
   // Call the base class first to paint any background/borders.
   View::OnPaint(canvas);