Handle app custom icon via aura::Window property.

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 e4fff6f17a71d2ddb9ce98a97105c2dec3b6f52f..d576f80ad4357fd4095a7906c03f51b1dc5af97a 100644
--- a/components/exo/shell_surface.cc
+++ b/components/exo/shell_surface.cc
@@ -48,6 +48,8 @@
 #include "chromeos/audio/chromeos_sounds.h"
 #endif
 
+DECLARE_UI_CLASS_PROPERTY_TYPE(exo::ShellSurface*)
+
 namespace exo {
 namespace {
 
@@ -312,6 +314,7 @@ ShellSurface::ScopedAnimationsDisabled::~ScopedAnimationsDisabled() {
 // ShellSurface, public:
 
 DEFINE_LOCAL_UI_CLASS_PROPERTY_KEY(Surface*, kMainSurfaceKey, nullptr)
+DEFINE_LOCAL_UI_CLASS_PROPERTY_KEY(ShellSurface*, kThisSurfaceKey, nullptr)
 
 ShellSurface::ShellSurface(Surface* surface,
                            ShellSurface* parent,
@@ -572,6 +575,20 @@ void ShellSurface::SetApplicationId(const std::string& application_id) {
     SetApplicationId(widget_->GetNativeWindow(), application_id);
 }
 
+// static
+void ShellSurface::SetAppIcon(aura::Window* window,
+                              const gfx::ImageSkia& icon) {
+  DCHECK(!GetApplicationId(window).empty());
+  ShellSurface* this_surface = window->GetProperty(kThisSurfaceKey);
+  if (this_surface) {
+    this_surface->icon_ = icon;
+    this_surface->widget_->UpdateWindowIcon();
+  } else {
+    // Support unit test case.
+    window->SetProperty(aura::client::kAppIconKey, new gfx::ImageSkia(icon));
+  }
+}
+
 void ShellSurface::Move() {
   TRACE_EVENT0("exo", "ShellSurface::Move");
 
@@ -857,6 +874,10 @@ base::string16 ShellSurface::GetWindowTitle() const {
   return title_;
 }
 
+gfx::ImageSkia ShellSurface::GetWindowIcon() {
+  return icon_;
+}
+
 void ShellSurface::SaveWindowPlacement(const gfx::Rect& bounds,
                                        ui::WindowShowState show_state) {
   if (bounds_mode_ != BoundsMode::CLIENT)
@@ -1201,6 +1222,7 @@ void ShellSurface::CreateShellSurfaceWidget(ui::WindowShowState show_state) {
   window->SetEventTargeter(base::WrapUnique(new CustomWindowTargeter(widget_)));
   SetApplicationId(window, application_id_);
   SetMainSurface(window, surface_);
+  window->SetProperty(kThisSurfaceKey, this);
 
   // Start tracking changes to window bounds and window state.
   window->AddObserver(this);