Rename ash desktop_background to wallpaper.

ash/display/window_tree_host_manager_unittest.cc

Index: ash/display/window_tree_host_manager_unittest.cc
diff --git a/ash/display/window_tree_host_manager_unittest.cc b/ash/display/window_tree_host_manager_unittest.cc
index ea8d9006d89c3432c2f66c402ea0389694d41174..2b97f578e469808e09ac166837e96fc12854e404 100644
--- a/ash/display/window_tree_host_manager_unittest.cc
+++ b/ash/display/window_tree_host_manager_unittest.cc
@@ -50,7 +50,7 @@
 namespace ash {
 namespace {
 
-const char kDesktopBackgroundView[] = "DesktopBackgroundView";
+const char kWallpaperView[] = "WallpaperView";
 
 template <typename T>
 class Resetter {
@@ -311,9 +311,9 @@ class TestEventHandler : public ui::EventHandler {
 
   void OnTouchEvent(ui::TouchEvent* event) override {
     aura::Window* target = static_cast<aura::Window*>(event->target());
-    // Only record when the target is the background which covers
-    // entire root window.
-    if (target->name() != kDesktopBackgroundView)
+    // Only record when the target is the wallpaper, which covers the entire
+    // root window.
+    if (target->name() != kWallpaperView)
       return;
     touch_radius_x_ = event->pointer_details().radius_x;
     touch_radius_y_ = event->pointer_details().radius_y;
@@ -322,9 +322,9 @@ class TestEventHandler : public ui::EventHandler {
 
   void OnScrollEvent(ui::ScrollEvent* event) override {
     aura::Window* target = static_cast<aura::Window*>(event->target());
-    // Only record when the target is the background which covers
-    // entire root window.
-    if (target->name() != kDesktopBackgroundView)
+    // Only record when the target is the wallpaper, which covers the entire
+    // root window.
+    if (target->name() != kWallpaperView)
       return;
 
     if (event->type() == ui::ET_SCROLL) {