Eliminate Shell::RootWindowList in favor of aura::Window::Windows.

ash/wm/partial_screenshot_view.cc

Index: ash/wm/partial_screenshot_view.cc
diff --git a/ash/wm/partial_screenshot_view.cc b/ash/wm/partial_screenshot_view.cc
index 66a4259dc85f45b4d21f97e63e159a2c661bc6be..b71c7c8a816347d76ab2cd2cabf22a35a5fa4312 100644
--- a/ash/wm/partial_screenshot_view.cc
+++ b/ash/wm/partial_screenshot_view.cc
@@ -84,8 +84,8 @@ PartialScreenshotView::StartPartialScreenshot(
     ScreenshotDelegate* screenshot_delegate) {
   std::vector<PartialScreenshotView*> views;
   OverlayDelegate* overlay_delegate = new OverlayDelegate();
-  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
-  for (Shell::RootWindowList::iterator it = root_windows.begin();
+  aura::Window::Windows root_windows = Shell::GetAllRootWindows();
+  for (aura::Window::Windows::iterator it = root_windows.begin();
        it != root_windows.end(); ++it) {
     PartialScreenshotView* new_view = new PartialScreenshotView(
         overlay_delegate, screenshot_delegate);
@@ -108,7 +108,7 @@ PartialScreenshotView::~PartialScreenshotView() {
   screenshot_delegate_ = NULL;
 }
 
-void PartialScreenshotView::Init(aura::RootWindow* root_window) {
+void PartialScreenshotView::Init(aura::Window* root_window) {
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);