Add a way to fetch window frame metrics from NativeShellWindow

chrome/browser/ui/cocoa/browser_window_cocoa.mm

Index: chrome/browser/ui/cocoa/browser_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index 1c875c6f7327da2e15e2576d9baac8267edfe507..9c5e39d76f0201810d66af4adef726c56c32ef67 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -225,6 +225,16 @@ bool BrowserWindowCocoa::IsAlwaysOnTop() const {
   return false;
 }
 
+gfx::Rect BrowserWindowCocoa::ContentBoundsForWindowBounds(
+    const gfx::Rect& window_bounds) const {
+  return window_bounds;
+}
+
+gfx::Rect BrowserWindowCocoa::WindowBoundsForContentBounds(
+    const gfx::Rect& content_bounds) const {
+  return content_bounds;
+}
+
 bool BrowserWindowCocoa::IsActive() const {
   return [window() isKeyWindow];
 }