Enable partial texture upload support for browser compositor with Surfaces

This requires that previously-used textures be returned to the browser compositor before a commit, so they can be uploaded to. This saves memory by reducing the number of textures that need to be created.

Also avoid releasing old textures from renderers on SubmitFrame, as that can be unnecessarily expensive if both the old and new frames reference the same textures.

BUG=446588,446417,446414

Review URL: https://codereview.chromium.org/843633003

Cr-Commit-Position: refs/heads/master@{#310737}

cc/output/delegating_renderer.cc

@@ -41,7 +41,8 @@ DelegatingRenderer::DelegatingRenderer(RendererClient* client,
   capabilities_.using_partial_swap = false;
   capabilities_.max_texture_size = resource_provider_->max_texture_size();
   capabilities_.best_texture_format = resource_provider_->best_texture_format();
-  capabilities_.allow_partial_texture_updates = false;
+  capabilities_.allow_partial_texture_updates =
+      output_surface->capabilities().can_force_reclaim_resources;
 
   if (!output_surface_->context_provider()) {
     capabilities_.using_shared_memory_resources = true;

cc/output/output_surface.h

@@ -64,7 +64,8 @@ class CC_EXPORT OutputSurface {
           draw_and_swap_full_viewport_every_frame(false),
           adjust_deadline_for_parent(true),
           uses_default_gl_framebuffer(true),
-          flipped_output_surface(false) {}
+          flipped_output_surface(false),
+          can_force_reclaim_resources(false) {}
     bool delegated_rendering;
     int max_frames_pending;
     bool deferred_gl_initialization;
@@ -77,6 +78,9 @@ class CC_EXPORT OutputSurface {
     bool uses_default_gl_framebuffer;
     // Whether this OutputSurface is flipped or not.
     bool flipped_output_surface;
+    // Whether ForceReclaimResources can be called to reclaim all resources
+    // from the OutputSurface.
+    bool can_force_reclaim_resources;
   };
 
   const Capabilities& capabilities() const {
@@ -111,6 +115,10 @@ class CC_EXPORT OutputSurface {
   virtual void Reshape(const gfx::Size& size, float scale_factor);
   virtual gfx::Size SurfaceSize() const;
 
+  // If supported, this causes a ReclaimResources for all resources that are
+  // currently in use.
+  virtual void ForceReclaimResources() {}
+
   virtual void BindFramebuffer();
 
   // The implementation may destroy or steal the contents of the CompositorFrame

cc/surfaces/display.cc

@@ -168,10 +168,16 @@ void Display::SetMemoryPolicy(const ManagedMemoryPolicy& policy) {
   client_->SetMemoryPolicy(policy);
 }
 
-void Display::OnSurfaceDamaged(SurfaceId surface) {
+void Display::OnSurfaceDamaged(SurfaceId surface_id) {
   if (aggregator_ &&
-      aggregator_->previous_contained_surfaces().count(surface)) {
-    aggregator_->ReleaseResources(surface);
+      aggregator_->previous_contained_surfaces().count(surface_id)) {
+    Surface* surface = manager_->GetSurfaceForId(surface_id);
+    if (surface) {
+      const CompositorFrame* current_frame = surface->GetEligibleFrame();
+      if (!current_frame || !current_frame->delegated_frame_data ||
+          !current_frame->delegated_frame_data->resource_list.size())
+        aggregator_->ReleaseResources(surface_id);
+    }
     client_->DisplayDamaged();
   }
 }

cc/trees/layer_tree_host_impl.cc

@@ -293,6 +293,12 @@ void LayerTreeHostImpl::BeginMainFrameAborted(CommitEarlyOutReason reason) {
 void LayerTreeHostImpl::BeginCommit() {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::BeginCommit");
 
+  // Ensure all textures are returned so partial texture updates can happen
+  // during the commit. Impl-side-painting doesn't upload during commits, so
+  // is unaffected.
+  if (!settings_.impl_side_painting)
+    output_surface_->ForceReclaimResources();
+
   if (UsePendingTreeForSync())
     CreatePendingTree();
 }

content/browser/compositor/surface_display_output_surface.cc

@@ -25,6 +25,7 @@ SurfaceDisplayOutputSurface::SurfaceDisplayOutputSurface(
       allocator_(allocator) {
   capabilities_.delegated_rendering = true;
   capabilities_.max_frames_pending = 1;
+  capabilities_.can_force_reclaim_resources = true;
 }
 
 SurfaceDisplayOutputSurface::~SurfaceDisplayOutputSurface() {
@@ -75,6 +76,15 @@ bool SurfaceDisplayOutputSurface::BindToClient(
   return display_client_->Initialize();
 }
 
+void SurfaceDisplayOutputSurface::ForceReclaimResources() {
+  if (!surface_id_.is_null()) {
+    scoped_ptr<cc::CompositorFrame> empty_frame(new cc::CompositorFrame());
+    empty_frame->delegated_frame_data.reset(new cc::DelegatedFrameData);
+    factory_.SubmitFrame(surface_id_, empty_frame.Pass(),
+                         cc::SurfaceFactory::DrawCallback());
+  }
+}
+
 void SurfaceDisplayOutputSurface::ReturnResources(
     const cc::ReturnedResourceArray& resources) {
   cc::CompositorFrameAck ack;

content/browser/compositor/surface_display_output_surface.h

@@ -41,6 +41,7 @@ class SurfaceDisplayOutputSurface : public cc::OutputSurface,
   // cc::OutputSurface implementation.
   void SwapBuffers(cc::CompositorFrame* frame) override;
   bool BindToClient(cc::OutputSurfaceClient* client) override;
+  void ForceReclaimResources() override;
 
   // cc::SurfaceFactoryClient implementation.
   void ReturnResources(const cc::ReturnedResourceArray& resources) override;