Handle UNPIN operation in ash.

ash/accelerators/accelerator_commands_unittest.cc

Index: ash/accelerators/accelerator_commands_unittest.cc
diff --git a/ash/accelerators/accelerator_commands_unittest.cc b/ash/accelerators/accelerator_commands_unittest.cc
index dfc164886652797c5f302e41484f3292a425a89a..eb25279c8f91659838359965cd786b0126c77617 100644
--- a/ash/accelerators/accelerator_commands_unittest.cc
+++ b/ash/accelerators/accelerator_commands_unittest.cc
@@ -9,6 +9,7 @@
 #include "ash/common/wm/window_state.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/wm/window_state_aura.h"
+#include "ash/wm/window_util.h"
 #include "ui/aura/window.h"
 
 // Note: The unit tests for |ToggleMaximized()| and
@@ -50,5 +51,18 @@ TEST_F(AcceleratorCommandsTest, ToggleMinimized) {
   EXPECT_TRUE(window_state1->IsActive());
 }
 
+TEST_F(AcceleratorCommandsTest, Unpin) {
+  std::unique_ptr<aura::Window> window1(
+      CreateTestWindowInShellWithBounds(gfx::Rect(5, 5, 20, 20)));
+  wm::WindowState* window_state1 = wm::GetWindowState(window1.get());
+  window_state1->Activate();
+
+  wm::PinWindow(window1.get());
+  EXPECT_TRUE(window_state1->IsPinned());
+
+  Unpin();
+  EXPECT_FALSE(window_state1->IsPinned());
+}
+
 }  // namespace accelerators
 }  // namespace ash