Add kApplicationIdKey for ShellSurface::GetApplicationId and SetApplicationId

components/exo/shell_surface_unittest.cc

Index: components/exo/shell_surface_unittest.cc
diff --git a/components/exo/shell_surface_unittest.cc b/components/exo/shell_surface_unittest.cc
index ab7cc8176d8dfadda17593da6e36723b0d08267f..338210ae8eab7dea573025f24559d3e3f45a60bb 100644
--- a/components/exo/shell_surface_unittest.cc
+++ b/components/exo/shell_surface_unittest.cc
@@ -250,9 +250,9 @@ TEST_F(ShellSurfaceTest, SetApplicationId) {
   surface->Attach(buffer.get());
   surface->Commit();
   aura::Window* window = shell_surface->GetWidget()->GetNativeWindow();
-  EXPECT_EQ("pre-widget-id", ShellSurface::GetApplicationId(window));
+  EXPECT_EQ("pre-widget-id", *ShellSurface::GetApplicationId(window));
   shell_surface->SetApplicationId("test");
-  EXPECT_EQ("test", ShellSurface::GetApplicationId(window));
+  EXPECT_EQ("test", *ShellSurface::GetApplicationId(window));
 }
 
 TEST_F(ShellSurfaceTest, Move) {