Increase app_shell default window size

Use 1366x768 because that matches most Chromebooks.

BUG=none
TEST=none

Review URL: https://codereview.chromium.org/334333003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@277673 0039d316-1c4b-4281-b951-d872f2087c98

apps/shell/browser/shell_desktop_controller.cc

@@ -235,7 +235,7 @@ void ShellDesktopController::CreateRootWindow() {
   // Set up basic pieces of ui::wm.
   gfx::Size size = GetPrimaryDisplaySize();
   if (size.IsEmpty())
-    size = gfx::Size(800, 600);
+    size = gfx::Size(1366, 768);
 
   host_.reset(aura::WindowTreeHost::Create(gfx::Rect(size)));
   host_->InitHost();