ui: Cleanup class/struct forward declarations

components/exo/shell_surface.cc

Index: components/exo/shell_surface.cc
diff --git a/components/exo/shell_surface.cc b/components/exo/shell_surface.cc
index 8247e8681a643410806db68ea103fb252a5194ec..92fb6e0772851f374ec0a5ad6072b55a8248ba85 100644
--- a/components/exo/shell_surface.cc
+++ b/components/exo/shell_surface.cc
@@ -43,6 +43,8 @@
 #include "chromeos/audio/chromeos_sounds.h"
 #endif
 
+DECLARE_WINDOW_PROPERTY_TYPE(std::string*)
+
 namespace exo {
 namespace {
 
@@ -327,6 +329,7 @@ ShellSurface::ScopedAnimationsDisabled::~ScopedAnimationsDisabled() {
 ////////////////////////////////////////////////////////////////////////////////
 // ShellSurface, public:
 
+DEFINE_LOCAL_WINDOW_PROPERTY_KEY(std::string*, kApplicationIdKey, nullptr)
 DEFINE_LOCAL_WINDOW_PROPERTY_KEY(Surface*, kMainSurfaceKey, nullptr)
 
 ShellSurface::ShellSurface(Surface* surface,
@@ -529,19 +532,21 @@ void ShellSurface::SetSystemModal(bool system_modal) {
 
 // static
 void ShellSurface::SetApplicationId(aura::Window* window,
-                                    const std::string& id) {
-  TRACE_EVENT1("exo", "ShellSurface::SetApplicationId", "application_id", id);
-  window->SetProperty(aura::client::kAppIdKey, new std::string(id));
+                                    std::string* application_id) {
+  window->SetProperty(kApplicationIdKey, application_id);
 }
 
 // static
 const std::string ShellSurface::GetApplicationId(aura::Window* window) {
-  std::string* string_ptr = window->GetProperty(aura::client::kAppIdKey);
+  std::string* string_ptr = window->GetProperty(kApplicationIdKey);
   return string_ptr ? *string_ptr : std::string();
 }
 
 void ShellSurface::SetApplicationId(const std::string& application_id) {
-  SetApplicationId(widget_->GetNativeWindow(), application_id);
+  TRACE_EVENT1("exo", "ShellSurface::SetApplicationId", "application_id",
+               application_id);
+
+  application_id_ = application_id;
 }
 
 void ShellSurface::Move() {
@@ -621,10 +626,7 @@ std::unique_ptr<base::trace_event::TracedValue> ShellSurface::AsTracedValue()
   std::unique_ptr<base::trace_event::TracedValue> value(
       new base::trace_event::TracedValue());
   value->SetString("title", base::UTF16ToUTF8(title_));
-  std::string application_id;
-  if (GetWidget() && GetWidget()->GetNativeWindow())
-    application_id = GetApplicationId(GetWidget()->GetNativeWindow());
-  value->SetString("application_id", application_id);
+  value->SetString("application_id", application_id_);
   return value;
 }
 
@@ -1021,6 +1023,7 @@ void ShellSurface::CreateShellSurfaceWidget(ui::WindowShowState show_state) {
   window->SetName("ExoShellSurface");
   window->AddChild(surface_->window());
   window->SetEventTargeter(base::WrapUnique(new CustomWindowTargeter(widget_)));
+  SetApplicationId(window, &application_id_);
   SetMainSurface(window, surface_);
 
   // Start tracking changes to window bounds and window state.