Add setBounds method and browsertest for get/set bounds to app window API

chrome/common/extensions/api/app_window.idl

Index: chrome/common/extensions/api/app_window.idl
diff --git a/chrome/common/extensions/api/app_window.idl b/chrome/common/extensions/api/app_window.idl
index b83984ba9cb7692d1cf630f599dba90083b973fd..e2d04aba5a38125b38dc1daca3b3419d42aea744 100644
--- a/chrome/common/extensions/api/app_window.idl
+++ b/chrome/common/extensions/api/app_window.idl
@@ -110,6 +110,9 @@ namespace app.window {
     // Hide the window. Does nothing if the window is already hidden.
     static void hide();
 
+    // Set the window's bounds.
+    static void setBounds(Bounds bounds);
+
     // The JavaScript 'window' object for the created child.
     [instanceOf=global] object contentWindow;
   };