Invalidate all wallpaper cache if display configuration changed

BUG=350406

Review URL: https://codereview.chromium.org/190993003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257440 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 8 insertions, 3 deletions

diff --git a/ash/desktop_background/desktop_background_controller.cc b/ash/desktop_background/desktop_background_controller.cc
index daf104e..7673f29 100644
--- a/ash/desktop_background/desktop_background_controller.cc
+++ b/ash/desktop_background/desktop_background_controller.cc
@@ -448,7 +448,7 @@ void DesktopBackgroundController::UpdateWallpaper() {
   current_default_wallpaper_path_ = base::FilePath();
   current_default_wallpaper_resource_id_ = -1;
   ash::Shell::GetInstance()->user_wallpaper_delegate()->
-      UpdateWallpaper();
+      UpdateWallpaper(true /* clear cache */);
 }
 
 // static
diff --git a/ash/desktop_background/user_wallpaper_delegate.h b/ash/desktop_background/user_wallpaper_delegate.h
index 16f2cf7..5e47ec0 100644
--- a/ash/desktop_background/user_wallpaper_delegate.h
+++ b/ash/desktop_background/user_wallpaper_delegate.h
@@ -30,8 +30,13 @@ class ASH_EXPORT UserWallpaperDelegate {
   virtual bool ShouldShowInitialAnimation() = 0;
 
   // Updates current wallpaper. It may switch the size of wallpaper based on the
-  // current display's resolution.
-  virtual void UpdateWallpaper() = 0;
+  // current display's resolution. If |clear_cache| is true, all wallpaper
+  // cache should be cleared. This is required when the display's native
+  // resolution changes to a larger resolution (e.g. when hooked up a large
+  // external display) and we need to load a larger resolution wallpaper for the
+  // large display. All the previous small resolution wallpaper cache should be
+  // cleared.
+  virtual void UpdateWallpaper(bool clear_cache) = 0;
 
   // Initialize wallpaper.
   virtual void InitializeWallpaper() = 0;