Add screen rotation animator lock.

ash/wallpaper/wallpaper_controller.cc

Index: ash/wallpaper/wallpaper_controller.cc
diff --git a/ash/wallpaper/wallpaper_controller.cc b/ash/wallpaper/wallpaper_controller.cc
index 15f2cc03cdf7ace5fa513b7cf1dcb48d6ec4e02f..d258a514c102568f735b55cf4f3b71259eaccfbf 100644
--- a/ash/wallpaper/wallpaper_controller.cc
+++ b/ash/wallpaper/wallpaper_controller.cc
@@ -10,6 +10,7 @@
 #include "ash/ash_switches.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
+#include "ash/rotator/screen_rotation_animator_lock.h"
 #include "ash/session/session_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_port.h"
@@ -153,6 +154,8 @@ void WallpaperController::SetWallpaperImage(const gfx::ImageSkia& image,
   current_wallpaper_.reset(new wallpaper::WallpaperResizer(
       image, GetMaxDisplaySizeInNative(), layout, task_runner_));
   current_wallpaper_->AddObserver(this);
+  if (screen_rotation_animator_lock_)
+    screen_rotation_animator_lock_->lock();
   current_wallpaper_->StartResize();
 
   for (auto& observer : observers_)
@@ -283,6 +286,8 @@ void WallpaperController::OnColorCalculationComplete() {
   const SkColor color = color_calculator_->prominent_color();
   color_calculator_.reset();
   SetProminentColor(color);
+  if (screen_rotation_animator_lock_)
+    screen_rotation_animator_lock_->unlock();
 }
 
 void WallpaperController::InstallDesktopController(WmWindow* root_window) {