External textures outlive layers.

When the View is hidden, we destroy the associated Layer, but the external texture should persist.

Similarly, if a View is made visible, we create a Layer and  the Layer should have that external texture.

The solution is to push the external texture logic and state up into the LayerHelper, which persists.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/7904024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@101388 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 35 insertions, 14 deletions

diff --git a/views/layer_helper.cc b/views/layer_helper.cc
index 6ba2b5e..6ffd34a 100644
--- a/views/layer_helper.cc
+++ b/views/layer_helper.cc
@@ -5,6 +5,7 @@
 #include "views/layer_helper.h"
 
 #include "views/layer_property_setter.h"
+#include "ui/gfx/compositor/compositor.h"
 #include "ui/gfx/compositor/layer.h"
 #include "ui/gfx/transform.h"
 
@@ -38,11 +39,19 @@ void LayerHelper::SetLayer(ui::Layer* layer) {
     if (!property_setter_.get())
       property_setter_.reset(LayerPropertySetter::CreateDefaultSetter());
     property_setter_->Installed(this->layer());
+    if (layer_updated_externally())
+      layer_->SetExternalTexture(external_texture_.get());
   } else if (!property_setter_explicitly_set_) {
     property_setter_.reset(NULL);
   }
 }
 
+void LayerHelper::SetExternalTexture(ui::Texture* texture) {
+  external_texture_ = texture;
+  if (layer_.get())
+    layer_->SetExternalTexture(texture);
+}
+
 void LayerHelper::SetPropertySetter(LayerPropertySetter* setter) {
   if (property_setter_.get() && layer())
     property_setter_->Uninstalled(layer());
@@ -55,7 +64,9 @@ void LayerHelper::SetPropertySetter(LayerPropertySetter* setter) {
 }
 
 bool LayerHelper::ShouldPaintToLayer() const {
-  return paint_to_layer_ || (transform_.get() && transform_->HasChange());
+  return paint_to_layer_ ||
+      layer_updated_externally() ||
+      (transform_.get() && transform_->HasChange());
 }
 
 } // namespace internal
diff --git a/views/layer_helper.h b/views/layer_helper.h
index 7417a4a..5246ae0 100644
--- a/views/layer_helper.h
+++ b/views/layer_helper.h
@@ -7,11 +7,13 @@
 #pragma once
 
 #include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/rect.h"
 
 namespace ui {
 class Layer;
+class Texture;
 class Transform;
 }
 
@@ -36,6 +38,15 @@ class LayerHelper {
   void SetLayer(ui::Layer* layer);
   ui::Layer* layer() { return layer_.get(); }
 
+  // Passing NULL will cause the layer to get a texture from its compositor.
+  void SetExternalTexture(ui::Texture* texture);
+
+  // Sometimes the Layer is being updated by something other than SetCanvas
+  // (e.g. the GPU process on TOUCH_UI).
+  bool layer_updated_externally() const {
+    return external_texture_.get() != NULL;
+  }
+
   // Rectangle that needs to be painted.
   void set_clip_rect(const gfx::Rect& rect) {
     clip_rect_ = rect;
@@ -91,6 +102,8 @@ class LayerHelper {
 
   bool needs_paint_all_;
 
+  scoped_refptr<ui::Texture> external_texture_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerHelper);
 };
 
diff --git a/views/view.cc b/views/view.cc
index dfd8f2f..b0f0b08 100644
--- a/views/view.cc
+++ b/views/view.cc
@@ -1116,25 +1116,15 @@ bool View::SetExternalTexture(ui::Texture* texture) {
 
   if (!layer_helper_.get())
     layer_helper_.reset(new internal::LayerHelper());
-  bool use_external = (texture != NULL);
-  if (use_external != layer_helper_->paint_to_layer())
-    SetPaintToLayer(use_external);
-  else if (use_external && !layer())
-    CreateLayer();
-
-  if (use_external && !layer())
-    return false;
+  layer_helper_->SetExternalTexture(texture);
 
   // Child views must not paint into the external texture. So make sure each
   // child view has its own layer to paint into.
-  if (use_external) {
+  if (texture) {
     for (Views::iterator i = children_.begin(); i != children_.end(); ++i)
       (*i)->SetPaintToLayer(true);
   }
 
-  if (layer())
-    layer()->SetExternalTexture(texture);
-
   SchedulePaintInRect(GetLocalBounds());
 
   return true;
@@ -1700,7 +1690,8 @@ void View::DestroyLayer() {
 
   if (!layer_helper_->property_setter_explicitly_set() &&
       !ShouldPaintToLayer() &&
-      !layer_helper_->fills_bounds_opaquely())
+      !layer_helper_->fills_bounds_opaquely() &&
+      !layer_helper_->layer_updated_externally())
     layer_helper_.reset();
   else
     layer_helper_->SetLayer(NULL);
diff --git a/views/widget/native_widget_view.cc b/views/widget/native_widget_view.cc
index 8037e9b..aa327c6 100644
--- a/views/widget/native_widget_view.cc
+++ b/views/widget/native_widget_view.cc
@@ -190,5 +190,10 @@ void NativeWidgetView::UpdateLayerBounds(const gfx::Point& offset) {
   }
 }
 
+void NativeWidgetView::CreateLayerIfNecessary() {
+  View::CreateLayerIfNecessary();
+  GetAssociatedWidget()->GetRootView()->CreateLayerIfNecessary();
+}
+
 }  // namespace internal
 }  // namespace views
diff --git a/views/widget/native_widget_view.h b/views/widget/native_widget_view.h
index f4b49cf..1d7f385 100644
--- a/views/widget/native_widget_view.h
+++ b/views/widget/native_widget_view.h
@@ -72,6 +72,7 @@ class VIEWS_EXPORT NativeWidgetView : public View {
                                  const gfx::Point& point) OVERRIDE;
   virtual void DestroyLayerRecurse() OVERRIDE;
   virtual void UpdateLayerBounds(const gfx::Point& offset) OVERRIDE;
+  virtual void CreateLayerIfNecessary() OVERRIDE;
 
   internal::NativeWidgetDelegate* delegate() {
     return native_widget_->delegate();