aura: Remove layerless windows.

ui/aura/window.cc

Index: ui/aura/window.cc
diff --git a/ui/aura/window.cc b/ui/aura/window.cc
index 3fe502797e0ccf5d30fda8393f2b91c4d6605f63..43d5955d4ab8e1833af88082647cf2851b4def3e 100644
--- a/ui/aura/window.cc
+++ b/ui/aura/window.cc
@@ -40,21 +40,6 @@ namespace aura {
 
 namespace {
 
-ui::LayerType WindowLayerTypeToUILayerType(WindowLayerType window_layer_type) {
-  switch (window_layer_type) {
-    case WINDOW_LAYER_NONE:
-      break;
-    case WINDOW_LAYER_NOT_DRAWN:
-      return ui::LAYER_NOT_DRAWN;
-    case WINDOW_LAYER_TEXTURED:
-      return ui::LAYER_TEXTURED;
-    case WINDOW_LAYER_SOLID_COLOR:
-      return ui::LAYER_SOLID_COLOR;
-  }
-  NOTREACHED();
-  return ui::LAYER_NOT_DRAWN;
-}
-
 // Used when searching for a Window to stack relative to.
 template <class T>
 T IteratorForDirectionBegin(aura::Window* window);
@@ -217,12 +202,9 @@ Window::Window(WindowDelegate* delegate)
 }
 
 Window::~Window() {
-  // |layer()| can be NULL during tests, or if this Window is layerless.
-  if (layer()) {
-    if (layer()->owner() == this)
-      layer()->CompleteAllAnimations();
-    layer()->SuppressPaint();
-  }
+  if (layer()->owner() == this)
+    layer()->CompleteAllAnimations();
+  layer()->SuppressPaint();
 
   // Let the delegate know we're in the processing of destroying.
   if (delegate_)
@@ -278,23 +260,18 @@ Window::~Window() {
   }
   prop_map_.clear();
 
-  // If we have layer it will either be destroyed by |layer_owner_|'s dtor, or
-  // by whoever acquired it. We don't have a layer if Init() wasn't invoked or
-  // we are layerless.
-  if (layer())
-    layer()->set_delegate(NULL);
+  // The layer will either be destroyed by |layer_owner_|'s dtor, or by whoever
+  // acquired it.
+  layer()->set_delegate(NULL);
   DestroyLayer();
 }
 
-void Window::Init(WindowLayerType window_layer_type) {
-  if (window_layer_type != WINDOW_LAYER_NONE) {
-    SetLayer(new ui::Layer(WindowLayerTypeToUILayerType(window_layer_type)));
-    layer()->SetVisible(false);
-    layer()->set_delegate(this);
-    UpdateLayerName();
-    layer()->SetFillsBoundsOpaquely(!transparent_);
-  }
-
+void Window::Init(ui::LayerType layer_type) {
+  SetLayer(new ui::Layer(layer_type));
+  layer()->SetVisible(false);
+  layer()->set_delegate(this);
+  UpdateLayerName();
+  layer()->SetFillsBoundsOpaquely(!transparent_);
   Env::GetInstance()->NotifyWindowInitialized(this);
 }
 
@@ -306,7 +283,6 @@ void Window::SetType(ui::wm::WindowType type) {
 
 void Window::SetName(const std::string& name) {
   name_ = name;
-
   if (layer())
     UpdateLayerName();
 }
@@ -325,8 +301,7 @@ void Window::SetTransparent(bool transparent) {
 }
 
 void Window::SetFillsBoundsCompletely(bool fills_bounds) {
-  if (layer())
-    layer()->SetFillsBoundsCompletely(fills_bounds);
+  layer()->SetFillsBoundsCompletely(fills_bounds);
 }
 
 Window* Window::GetRootWindow() {
@@ -349,13 +324,11 @@ const WindowTreeHost* Window::GetHost() const {
 }
 
 void Window::Show() {
-  if (layer()) {
-    DCHECK_EQ(visible_, layer()->GetTargetVisibility());
-    // It is not allowed that a window is visible but the layers alpha is fully
-    // transparent since the window would still be considered to be active but
-    // could not be seen.
-    DCHECK(!(visible_ && layer()->GetTargetOpacity() == 0.0f));
-  }
+  DCHECK_EQ(visible_, layer()->GetTargetVisibility());
+  // It is not allowed that a window is visible but the layers alpha is fully
+  // transparent since the window would still be considered to be active but
+  // could not be seen.
+  DCHECK_IMPLIES(visible_, layer()->GetTargetOpacity() > 0.0f);
   SetVisible(true);
 }
 
@@ -490,17 +463,7 @@ gfx::Rect Window::GetTargetBounds() const {
 }
 
 void Window::SchedulePaintInRect(const gfx::Rect& rect) {
-  if (!layer() && parent_) {
-    // Notification of paint scheduled happens for the window with a layer.
-    gfx::Rect parent_rect(bounds().size());
-    parent_rect.Intersect(rect);
-    if (!parent_rect.IsEmpty()) {
-      parent_rect.Offset(bounds().origin().OffsetFromOrigin());
-      parent_->SchedulePaintInRect(parent_rect);
-    }
-  } else if (layer()) {
-    layer()->SchedulePaint(rect);
-  }
+  layer()->SchedulePaint(rect);
 }
 
 void Window::StackChildAtTop(Window* child) {
@@ -788,8 +751,7 @@ bool Window::HasCapture() {
 }
 
 void Window::SuppressPaint() {
-  if (layer())
-    layer()->SuppressPaint();
+  layer()->SuppressPaint();
 }
 
 // {Set,Get,Clear}Property are implemented in window_property.h.
@@ -942,7 +904,7 @@ void Window::SetVisible(bool visible) {
       client::GetVisibilityClient(this);
   if (visibility_client)
     visibility_client->UpdateLayerVisibility(this, visible);
-  else if (layer())
+  else
     layer()->SetVisible(visible);
   visible_ = visible;
   SchedulePaint();
@@ -962,21 +924,6 @@ void Window::SchedulePaint() {
 void Window::Paint(gfx::Canvas* canvas) {
   if (delegate_)
     delegate_->OnPaint(canvas);
-  PaintLayerlessChildren(canvas);
-}
-
-void Window::PaintLayerlessChildren(gfx::Canvas* canvas) {
-  for (size_t i = 0, count = children_.size(); i < count; ++i) {
-    Window* child = children_[i];
-    if (!child->layer() && child->visible_) {
-      gfx::ScopedCanvas scoped_canvas(canvas);
-      canvas->ClipRect(child->bounds());
-      if (!canvas->IsClipEmpty()) {
-        canvas->Translate(child->bounds().OffsetFromOrigin());
-        child->Paint(canvas);
-      }
-    }
-  }
 }
 
 Window* Window::GetWindowForPoint(const gfx::Point& local_point,
@@ -1344,15 +1291,12 @@ void Window::NotifyAncestorWindowTransformed(Window* source) {
 }
 
 void Window::OnWindowBoundsChanged(const gfx::Rect& old_bounds) {
-  if (layer()) {
-    bounds_ = layer()->bounds();
-    if (parent_ && !parent_->layer()) {
-      gfx::Vector2d offset;
-      aura::Window* ancestor_with_layer =
-          parent_->GetAncestorWithLayer(&offset);
-      if (ancestor_with_layer)
-        bounds_.Offset(-offset);
-    }
+  bounds_ = layer()->bounds();
+  if (parent_ && !parent_->layer()) {
+    gfx::Vector2d offset;
+    aura::Window* ancestor_with_layer = parent_->GetAncestorWithLayer(&offset);
+    if (ancestor_with_layer)
+      bounds_.Offset(-offset);
   }
 
   if (layout_manager_)