Convert Layer's LayerClient to a WeakPtr.

Bug: 813520
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: I3f5b734202c69346c4681c11a40ebb58922f7e64
Reviewed-on: https://chromium-review.googlesource.com/969587Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Reviewed-by: Ian Vollick <vollick@chromium.org>
Commit-Queue: Robert Flack <flackr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544359}

cc/blink/web_layer_impl.cc

@@ -460,8 +460,8 @@ void WebLayerImpl::SetScrollOffsetFromImplSideForTesting(
   layer_->SetScrollOffsetFromImplSide(offset);
 }
 
-void WebLayerImpl::SetLayerClient(cc::LayerClient* client) {
-  layer_->SetLayerClient(client);
+void WebLayerImpl::SetLayerClient(base::WeakPtr<cc::LayerClient> client) {
+  layer_->SetLayerClient(std::move(client));
 }
 
 const cc::Layer* WebLayerImpl::CcLayer() const {

cc/blink/web_layer_impl.h

@@ -122,7 +122,7 @@ class CC_BLINK_EXPORT WebLayerImpl : public blink::WebLayer {
       const override;
   void SetScrollClient(blink::WebLayerScrollClient* client) override;
   void SetScrollOffsetFromImplSideForTesting(const gfx::ScrollOffset&) override;
-  void SetLayerClient(cc::LayerClient* client) override;
+  void SetLayerClient(base::WeakPtr<cc::LayerClient> client) override;
   const cc::Layer* CcLayer() const override;
   cc::Layer* CcLayer() override;
   void SetElementId(const cc::ElementId&) override;

cc/layers/layer.h

@@ -335,7 +335,9 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
   TakeDebugInfo();
   virtual void didUpdateMainThreadScrollingReasons();
 
-  void SetLayerClient(LayerClient* client) { inputs_.client = client; }
+  void SetLayerClient(base::WeakPtr<LayerClient> client) {
+    inputs_.client = std::move(client);
+  }
 
   virtual bool IsSnapped();
 
@@ -627,7 +629,7 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
     bool hide_layer_and_subtree : 1;
 
     // The following elements can not and are not serialized.
-    LayerClient* client;
+    base::WeakPtr<LayerClient> client;
     base::Callback<void(const gfx::ScrollOffset&, const ElementId&)>
         did_scroll_callback;
     std::vector<std::unique_ptr<viz::CopyOutputRequest>> copy_requests;

third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp

@@ -105,13 +105,14 @@ GraphicsLayer::GraphicsLayer(GraphicsLayerClient& client)
       contents_layer_(nullptr),
       contents_layer_id_(0),
       scrollable_area_(nullptr),
-      rendering_context3d_(0) {
+      rendering_context3d_(0),
+      weak_ptr_factory_(this) {
 #if DCHECK_IS_ON()
   client.VerifyNotPainting();
 #endif
   layer_ = Platform::Current()->CompositorSupport()->CreateContentLayer(this);
   layer_->Layer()->SetDrawsContent(draws_content_ && contents_visible_);
-  layer_->Layer()->SetLayerClient(this);
+  layer_->Layer()->SetLayerClient(weak_ptr_factory_.GetWeakPtr());
 
   UpdateTrackingRasterInvalidations();
 }
@@ -556,7 +557,7 @@ void GraphicsLayer::SetContentsLayer(WebLayer* contents_layer) {
     contents_layer_id_ = 0;
     return;
   }
-  contents_layer_->SetLayerClient(this);
+  contents_layer_->SetLayerClient(weak_ptr_factory_.GetWeakPtr());
   contents_layer_id_ = contents_layer_->Id();
 }
 
@@ -1292,7 +1293,7 @@ void GraphicsLayer::SetPaintingPhase(GraphicsLayerPaintingPhase phase) {
 void GraphicsLayer::AddLinkHighlight(LinkHighlight* link_highlight) {
   DCHECK(link_highlight && !link_highlights_.Contains(link_highlight));
   link_highlights_.push_back(link_highlight);
-  link_highlight->Layer()->SetLayerClient(this);
+  link_highlight->Layer()->SetLayerClient(weak_ptr_factory_.GetWeakPtr());
   UpdateChildList();
 }
 

third_party/WebKit/Source/platform/graphics/GraphicsLayer.h

@@ -28,6 +28,7 @@
 #define GraphicsLayer_h
 
 #include <memory>
+#include "base/memory/weak_ptr.h"
 #include "cc/layers/layer_client.h"
 #include "platform/PlatformExport.h"
 #include "platform/geometry/FloatPoint.h"
@@ -430,6 +431,8 @@ class PLATFORM_EXPORT GraphicsLayer : public cc::LayerClient,
   std::unique_ptr<LayerState> layer_state_;
 
   std::unique_ptr<CompositedLayerRasterInvalidator> raster_invalidator_;
+
+  base::WeakPtrFactory<GraphicsLayer> weak_ptr_factory_;
 };
 
 // ObjectPaintInvalidatorWithContext::InvalidatePaintRectangleWithContext uses

third_party/WebKit/public/platform/WebLayer.h

@@ -241,7 +241,7 @@ class WebLayer {
   virtual void SetSnapContainerData(base::Optional<cc::SnapContainerData>) = 0;
 
   // Sets the cc-side layer client.
-  virtual void SetLayerClient(cc::LayerClient*) = 0;
+  virtual void SetLayerClient(base::WeakPtr<cc::LayerClient>) = 0;
 
   // Gets the underlying cc layer.
   virtual const cc::Layer* CcLayer() const = 0;

ui/compositor/layer.cc

@@ -113,7 +113,8 @@ Layer::Layer()
       device_scale_factor_(1.0f),
       cache_render_surface_requests_(0),
       deferred_paint_requests_(0),
-      trilinear_filtering_request_(0) {
+      trilinear_filtering_request_(0),
+      weak_ptr_factory_(this) {
   CreateCcLayer();
 }
 
@@ -140,7 +141,8 @@ Layer::Layer(LayerType type)
       device_scale_factor_(1.0f),
       cache_render_surface_requests_(0),
       deferred_paint_requests_(0),
-      trilinear_filtering_request_(0) {
+      trilinear_filtering_request_(0),
+      weak_ptr_factory_(this) {
   CreateCcLayer();
 }
 
@@ -628,7 +630,7 @@ void Layer::SwitchToLayer(scoped_refptr<cc::Layer> new_layer) {
     DCHECK(child->cc_layer_);
     cc_layer_->AddChild(child->cc_layer_);
   }
-  cc_layer_->SetLayerClient(this);
+  cc_layer_->SetLayerClient(weak_ptr_factory_.GetWeakPtr());
   cc_layer_->SetTransformOrigin(gfx::Point3F());
   cc_layer_->SetContentsOpaque(fills_bounds_opaquely_);
   cc_layer_->SetIsDrawable(type_ != LAYER_NOT_DRAWN);
@@ -1263,7 +1265,7 @@ void Layer::CreateCcLayer() {
   cc_layer_->SetTransformOrigin(gfx::Point3F());
   cc_layer_->SetContentsOpaque(true);
   cc_layer_->SetIsDrawable(type_ != LAYER_NOT_DRAWN);
-  cc_layer_->SetLayerClient(this);
+  cc_layer_->SetLayerClient(weak_ptr_factory_.GetWeakPtr());
   cc_layer_->SetElementId(cc::ElementId(cc_layer_->id()));
   RecomputePosition();
 }

ui/compositor/layer.h

@@ -14,6 +14,7 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/observer_list.h"
 #include "cc/base/region.h"
@@ -623,6 +624,8 @@ class COMPOSITOR_EXPORT Layer : public LayerAnimationDelegate,
   // layer.
   unsigned trilinear_filtering_request_;
 
+  base::WeakPtrFactory<Layer> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };