Re-implement overscan & Implement Display Rotation

ash/desktop_background/desktop_background_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/desktop_background/desktop_background_controller.h"
 
 #include "ash/desktop_background/desktop_background_controller_observer.h"
 #include "ash/desktop_background/desktop_background_view.h"
 #include "ash/desktop_background/desktop_background_widget_controller.h"
 #include "ash/desktop_background/user_wallpaper_delegate.h"
@@ skipping 232 matching lines @@
   current_wallpaper_.reset(NULL);
   SetDesktopBackgroundImageMode();
 }
 
 WallpaperResolution DesktopBackgroundController::GetAppropriateResolution() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   WallpaperResolution resolution = WALLPAPER_RESOLUTION_SMALL;
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
   for (Shell::RootWindowList::iterator iter = root_windows.begin();
        iter != root_windows.end(); ++iter) {
-    gfx::Size root_window_size = (*iter)->GetHostSize();
-    if (root_window_size.width() > kSmallWallpaperMaxWidth ||
-        root_window_size.height() > kSmallWallpaperMaxHeight) {
+    // Compare to host size as constants are defined in terms of
+    // physical pixel size.
+    // TODO(oshima): This may not be ideal for fractional scaling
+    // scenario. Revisit and fix if necessary.
+    gfx::Size host_window_size = (*iter)->GetHostSize();
+    if (host_window_size.width() > kSmallWallpaperMaxWidth ||
+        host_window_size.height() > kSmallWallpaperMaxHeight) {
       resolution = WALLPAPER_RESOLUTION_LARGE;
     }
   }
   return resolution;
 }
 
 bool DesktopBackgroundController::MoveDesktopToLockedContainer() {
   if (locked_)
     return false;
   locked_ = true;
@@ skipping 134 matching lines @@
   }
   return moved;
 }
 
 int DesktopBackgroundController::GetBackgroundContainerId(bool locked) {
   return locked ? internal::kShellWindowId_LockScreenBackgroundContainer :
                   internal::kShellWindowId_DesktopBackgroundContainer;
 }
 
 }  // namespace ash