Enable user change background image in settings page in Aura build.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 1041a3dca9a50ecf3f495b991bf89648d1935c41..622acdf0c45bef9f8bbfd3e0978e9b96303b4eef 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -8,6 +8,9 @@
 
 #include "ash/app_list/app_list.h"
 #include "ash/ash_switches.h"
+#include "ash/desktop_background/desktop_background_controller.h"
+#include "ash/desktop_background/desktop_background_resources.h"
+#include "ash/desktop_background/desktop_background_view.h"
 #include "ash/drag_drop/drag_drop_controller.h"
 #include "ash/focus_cycler.h"
 #include "ash/ime/input_method_event_filter.h"
@@ -478,6 +481,7 @@ void Shell::Init() {
   AddRootWindowEventFilter(tooltip_controller_.get());
 
   drag_drop_controller_.reset(new internal::DragDropController);
+  desktop_background_controller_.reset(new DesktopBackgroundController);
   power_button_controller_.reset(new PowerButtonController);
   video_detector_.reset(new VideoDetector);
   window_cycle_controller_.reset(new WindowCycleController);
@@ -538,25 +542,34 @@ void Shell::ToggleAppList() {
   app_list_->SetVisible(!app_list_->IsVisible());
 }
 
-void Shell::SetDesktopBackgroundMode(BackgroundMode mode) {
-  if (mode == BACKGROUND_SOLID_COLOR) {
-    // Set a solid black background.
-    // TODO(derat): Remove this in favor of having the compositor only clear the
-    // viewport when there are regions not covered by a layer:
-    // http://crbug.com/113445
-    ui::Layer* background_layer = new ui::Layer(ui::Layer::LAYER_SOLID_COLOR);
-    background_layer->SetColor(SK_ColorBLACK);
-    GetContainer(internal::kShellWindowId_DesktopBackgroundContainer)->
-        layer()->Add(background_layer);
-    root_window_layout_->SetBackgroundLayer(background_layer);
-    root_window_layout_->SetBackgroundWidget(NULL);
-  } else {
-    // Create the desktop background image.
-    root_window_layout_->SetBackgroundLayer(NULL);
-    root_window_layout_->SetBackgroundWidget(
-        internal::CreateDesktopBackground());
-  }
-  desktop_background_mode_ = mode;
+void Shell::SetDesktopBackgroundWallpaper(const SkBitmap& wallpaper) {
+  if (desktop_background_mode_ == BACKGROUND_SOLID_COLOR)
+    return;
+  DCHECK(root_window_layout_->background_widget());
+  static_cast<internal::DesktopBackgroundView*>(
+      root_window_layout_->background_widget()->widget_delegate())->
+      SetWallpaper(wallpaper);
+}
+
+void Shell::SetDesktopBackgrondImage(const SkBitmap& wallpaper) {
+  root_window_layout_->SetBackgroundLayer(NULL);
+  root_window_layout_->SetBackgroundWidget(
+      internal::CreateDesktopBackground(wallpaper));
+  desktop_background_mode_ = BACKGROUND_IMAGE;
+}
+
+void Shell::SetDesktopBackgroundSolidColor() {
+  // Set a solid black background.
+  // TODO(derat): Remove this in favor of having the compositor only clear the
+  // viewport when there are regions not covered by a layer:
+  // http://crbug.com/113445
+  ui::Layer* background_layer = new ui::Layer(ui::Layer::LAYER_SOLID_COLOR);
+  background_layer->SetColor(SK_ColorBLACK);
+  GetContainer(internal::kShellWindowId_DesktopBackgroundContainer)->
+      layer()->Add(background_layer);
+  root_window_layout_->SetBackgroundLayer(background_layer);
+  root_window_layout_->SetBackgroundWidget(NULL);
+  desktop_background_mode_ = BACKGROUND_SOLID_COLOR;
 }
 
 bool Shell::IsScreenLocked() const {
@@ -635,7 +648,7 @@ void Shell::SetupCompactWindowMode() {
   launcher_->widget()->Hide();
 
   // Set a solid black background.
-  SetDesktopBackgroundMode(BACKGROUND_SOLID_COLOR);
+  SetDesktopBackgroundSolidColor();
 }
 
 void Shell::SetupManagedWindowMode() {
@@ -664,7 +677,8 @@ void Shell::SetupManagedWindowMode() {
   launcher_->widget()->Show();
 
   // Create the desktop background image.
-  SetDesktopBackgroundMode(BACKGROUND_IMAGE);
+  SetDesktopBackgrondImage(desktop_background_controller_->
+                           GetPresetWallpaper());
 }
 
 void Shell::ResetLayoutManager(int container_id) {