Attach panel while dragging to bring it in front of other panels.

ash/wm/panels/panel_window_resizer_unittest.cc

Index: ash/wm/panels/panel_window_resizer_unittest.cc
diff --git a/ash/wm/panels/panel_window_resizer_unittest.cc b/ash/wm/panels/panel_window_resizer_unittest.cc
index 4be464567b906f15ba5f803a969bc6b789c5f3fc..8f108d323bff2f73acc6a0df425a32bbd75a1d98 100644
--- a/ash/wm/panels/panel_window_resizer_unittest.cc
+++ b/ash/wm/panels/panel_window_resizer_unittest.cc
@@ -103,6 +103,7 @@ class PanelWindowResizerTest : public test::AshTestBase {
   // dragging out by the vector (dx, dy).
   void DetachReattachTest(int dx, int dy) {
     EXPECT_TRUE(window_->GetProperty(kPanelAttachedKey));
+    EXPECT_EQ(internal::kShellWindowId_PanelContainer, window_->parent()->id());
     DragStart();
     gfx::Rect initial_bounds = window_->bounds();
 
@@ -120,6 +121,8 @@ class PanelWindowResizerTest : public test::AshTestBase {
     // The panel should be detached when the drag completes.
     DragEnd();
     EXPECT_FALSE(window_->GetProperty(kPanelAttachedKey));
+    EXPECT_EQ(internal::kShellWindowId_WorkspaceContainer,
+              window_->parent()->id());
 
     DragStart();
     // Drag the panel down.
@@ -131,6 +134,7 @@ class PanelWindowResizerTest : public test::AshTestBase {
     EXPECT_TRUE(window_->GetProperty(kPanelAttachedKey));
     EXPECT_EQ(initial_bounds.x(), window_->bounds().x());
     EXPECT_EQ(initial_bounds.y(), window_->bounds().y());
+    EXPECT_EQ(internal::kShellWindowId_PanelContainer, window_->parent()->id());
   }
 
   aura::test::TestWindowDelegate delegate_;
@@ -177,5 +181,23 @@ TEST_F(PanelWindowResizerTest, PanelDetachReattachTop) {
   DetachReattachTest(0, 1);
 }
 
+TEST_F(PanelWindowResizerTest, DragMovesToPanelLayer) {
+  DragStart();
+  DragMove(0, -100);
+  DragEnd();
+  EXPECT_EQ(internal::kShellWindowId_WorkspaceContainer,
+            window_->parent()->id());
+
+  // While moving the panel window should be moved to the panel container.
+  DragStart();
+  DragMove(20, 0);
+  EXPECT_EQ(internal::kShellWindowId_PanelContainer, window_->parent()->id());
+  DragEnd();
+
+  // When dropped it should return to the default container.
+  EXPECT_EQ(internal::kShellWindowId_WorkspaceContainer,
+            window_->parent()->id());
+}
+
 }  // namespace internal
 }  // namespace ash