Reland - cros: Add CHECK for screen unlock problem

On some devices when you unlock the screen after suspend the launcher and
desktop windows do not appear. I suspect the background widget is not being
reparented properly but I cannot reproduce the problem internally.  Since
the user can't recover from this state without rebooting, add some CHECKs
to try to track down the source.

Also initialize empty wallpaper if we're running tests, as we previously
skipped it which would cause my CHECKs to be hit.

BUG=149043
TEST=ScreenLockerTest and manual, lock screen with Ctrl-Shift-L, unlock by entering password


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=158846

Reverted: http://src.chromium.org/viewvc/chrome?view=rev&revision=159154

Review URL: https://chromiumcodereview.appspot.com/10982035

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@159636 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 30 insertions, 21 deletions

diff --git a/ash/desktop_background/desktop_background_controller.cc b/ash/desktop_background/desktop_background_controller.cc
index b1ca185..6f4d11b 100644
--- a/ash/desktop_background/desktop_background_controller.cc
+++ b/ash/desktop_background/desktop_background_controller.cc
@@ -237,20 +237,20 @@ WallpaperResolution DesktopBackgroundController::GetAppropriateResolution() {
   return resolution;
 }
 
-void DesktopBackgroundController::MoveDesktopToLockedContainer() {
+bool DesktopBackgroundController::MoveDesktopToLockedContainer() {
   if (locked_)
-    return;
+    return false;
   locked_ = true;
-  ReparentBackgroundWidgets(GetBackgroundContainerId(false),
-                            GetBackgroundContainerId(true));
+  return ReparentBackgroundWidgets(GetBackgroundContainerId(false),
+                                   GetBackgroundContainerId(true));
 }
 
-void DesktopBackgroundController::MoveDesktopToUnlockedContainer() {
+bool DesktopBackgroundController::MoveDesktopToUnlockedContainer() {
   if (!locked_)
-    return;
+    return false;
   locked_ = false;
-  ReparentBackgroundWidgets(GetBackgroundContainerId(true),
-                            GetBackgroundContainerId(false));
+  return ReparentBackgroundWidgets(GetBackgroundContainerId(true),
+                                   GetBackgroundContainerId(false));
 }
 
 void DesktopBackgroundController::OnWindowDestroying(aura::Window* window) {
@@ -336,8 +336,9 @@ void DesktopBackgroundController::InstallComponentForAllWindows() {
   }
 }
 
-void DesktopBackgroundController::ReparentBackgroundWidgets(int src_container,
+bool DesktopBackgroundController::ReparentBackgroundWidgets(int src_container,
                                                             int dst_container) {
+  bool moved = false;
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
   for (Shell::RootWindowList::iterator iter = root_windows.begin();
     iter != root_windows.end(); ++iter) {
@@ -352,11 +353,12 @@ void DesktopBackgroundController::ReparentBackgroundWidgets(int src_container,
             GetComponent(false);
       }
       DCHECK(component);
-      component->Reparent(root_window,
-                          src_container,
-                          dst_container);
+      moved = moved || component->Reparent(root_window,
+                                           src_container,
+                                           dst_container);
     }
   }
+  return moved;
 }
 
 int DesktopBackgroundController::GetBackgroundContainerId(bool locked) {
diff --git a/ash/desktop_background/desktop_background_controller.h b/ash/desktop_background/desktop_background_controller.h
index 0251c1c..8976a31 100644
--- a/ash/desktop_background/desktop_background_controller.h
+++ b/ash/desktop_background/desktop_background_controller.h
@@ -120,10 +120,12 @@ class ASH_EXPORT DesktopBackgroundController : public aura::WindowObserver {
   WallpaperResolution GetAppropriateResolution();
 
   // Move all desktop widgets to locked container.
-  void MoveDesktopToLockedContainer();
+  // Returns true if the desktop moved.
+  bool MoveDesktopToLockedContainer();
 
   // Move all desktop widgets to unlocked container.
-  void MoveDesktopToUnlockedContainer();
+  // Returns true if the desktop moved.
+  bool MoveDesktopToUnlockedContainer();
 
   // WindowObserver implementation.
   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
@@ -155,9 +157,9 @@ class ASH_EXPORT DesktopBackgroundController : public aura::WindowObserver {
   // all root windows.
   void InstallComponentForAllWindows();
 
-  // Moves all descktop components from one container to other across all root
-  // windows.
-  void ReparentBackgroundWidgets(int src_container, int dst_container);
+  // Moves all desktop components from one container to other across all root
+  // windows. Returns true if a desktop moved.
+  bool ReparentBackgroundWidgets(int src_container, int dst_container);
 
   // Returns id for background container for unlocked and locked states.
   int GetBackgroundContainerId(bool locked);
diff --git a/ash/desktop_background/desktop_background_widget_controller.cc b/ash/desktop_background/desktop_background_widget_controller.cc
index 9ad1f95..6b796d0 100644
--- a/ash/desktop_background/desktop_background_widget_controller.cc
+++ b/ash/desktop_background/desktop_background_widget_controller.cc
@@ -49,17 +49,22 @@ void DesktopBackgroundWidgetController::SetBounds(gfx::Rect bounds) {
     layer_->SetBounds(bounds);
 }
 
-void DesktopBackgroundWidgetController::Reparent(aura::RootWindow* root_window,
+bool DesktopBackgroundWidgetController::Reparent(aura::RootWindow* root_window,
                                                  int src_container,
                                                  int dest_container) {
   if (widget_) {
     views::Widget::ReparentNativeView(widget_->GetNativeView(),
         root_window->GetChildById(dest_container));
-  } else if (layer_.get()) {
+    return true;
+  }
+  if (layer_.get()) {
     ui::Layer* layer = layer_.get();
     root_window->GetChildById(src_container)->layer()->Remove(layer);
     root_window->GetChildById(dest_container)->layer()->Add(layer);
+    return true;
   }
+  // Nothing to reparent.
+  return false;
 }
 
 ComponentWrapper::ComponentWrapper(
diff --git a/ash/desktop_background/desktop_background_widget_controller.h b/ash/desktop_background/desktop_background_widget_controller.h
index d565332..7017eb0 100644
--- a/ash/desktop_background/desktop_background_widget_controller.h
+++ b/ash/desktop_background/desktop_background_widget_controller.h
@@ -37,8 +37,8 @@ class DesktopBackgroundWidgetController : public views::WidgetObserver {
 
   // Move component from |src_container| in |root_window| to |dest_container|.
   // It is required for lock screen, when we need to move background so that
-  // it hides user's windows.
-  void Reparent(aura::RootWindow* root_window,
+  // it hides user's windows. Returns true if there was something to reparent.
+  bool Reparent(aura::RootWindow* root_window,
                 int src_container,
                 int dest_container);