[ash] Don't remove an item when associated window is dragged

ash/shelf/shelf_window_watcher_unittest.cc

Index: ash/shelf/shelf_window_watcher_unittest.cc
diff --git a/ash/shelf/shelf_window_watcher_unittest.cc b/ash/shelf/shelf_window_watcher_unittest.cc
index 1217aae2e5ecb048efa0850646722c290b2d25a9..899c19cdcde7a69d8c0f370282d83805a959ffa5 100644
--- a/ash/shelf/shelf_window_watcher_unittest.cc
+++ b/ash/shelf/shelf_window_watcher_unittest.cc
@@ -10,10 +10,12 @@
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/shell_test_api.h"
+#include "ash/wm/window_resizer.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/window.h"
+#include "ui/base/hit_test.h"
 
 namespace ash {
 namespace internal {
@@ -166,7 +168,35 @@ TEST_F(ShelfWindowWatcherTest, MaximizeAndRestoreWindow) {
   EXPECT_FALSE(window_state->IsMaximized());
   // No new item is created after restoring a window |window|.
   EXPECT_EQ(2, model_->item_count());
-  // index and id are not changed after maximizing a window |window|.
+  // Index and id are not changed after maximizing a window |window|.
+  EXPECT_EQ(index, model_->ItemIndexByID(id));
+  EXPECT_EQ(id, model_->items()[index].id);
+}
+
+TEST_F(ShelfWindowWatcherTest, DragWindow) {
+  // ShelfModel only has an APP_LIST item.
+  EXPECT_EQ(1, model_->item_count());
+
+  scoped_ptr<aura::Window> window(CreateTestWindowInShellWithId(0));
+
+  // Create a LauncherItem for |window|.
+  LauncherID id = CreateLauncherItem(window.get());
+  EXPECT_EQ(2, model_->item_count());
+
+  int index = model_->ItemIndexByID(id);
+  EXPECT_EQ(STATUS_RUNNING, model_->items()[index].status);
+
+  // Simulate dragging of |window|.
+  scoped_ptr<WindowResizer> resizer(
+      CreateWindowResizer(window.get(),
+                          gfx::Point(),
+                          HTCAPTION,
+                          aura::client::WINDOW_MOVE_SOURCE_MOUSE));
+  ASSERT_TRUE(resizer.get());
+  resizer->Drag(gfx::Point(50, 50), 0);
+  resizer->CompleteDrag(0);
+
+  //Index and id are not changed after dragging a |window|.
   EXPECT_EQ(index, model_->ItemIndexByID(id));
   EXPECT_EQ(id, model_->items()[index].id);
 }