cc: Stop using transfer buffer limit for 1-copy rasterizer.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 111 matching lines @@
     return GL_TEXTURE_2D;
 
   if (context_provider->ContextCapabilities().gpu.egl_image_external)
     return GL_TEXTURE_EXTERNAL_OES;
   if (context_provider->ContextCapabilities().gpu.texture_rectangle)
     return GL_TEXTURE_RECTANGLE_ARB;
 
   return GL_TEXTURE_2D;
 }
 
+size_t GetMaxStagingResourceCount() {
+  // Upper bound for number of staging resource to allow.
+  return 32;
+}
+
 }  // namespace
 
 namespace cc {
 
 class LayerTreeHostImplTimeSourceAdapter : public TimeSourceClient {
  public:
   static scoped_ptr<LayerTreeHostImplTimeSourceAdapter> Create(
       LayerTreeHostImpl* layer_tree_host_impl,
       scoped_refptr<DelayBasedTimeSource> time_source) {
     return make_scoped_ptr(
@@ skipping 115 matching lines @@
       zero_budget_(false),
       device_scale_factor_(1.f),
       overhang_ui_resource_id_(0),
       resourceless_software_draw_(false),
       begin_impl_frame_interval_(BeginFrameArgs::DefaultInterval()),
       animation_registrar_(AnimationRegistrar::Create()),
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
       micro_benchmark_controller_(this),
       need_to_update_visible_tiles_before_draw_(false),
       shared_bitmap_manager_(manager),
-      id_(id),
-      transfer_buffer_memory_limit_(0u) {
+      id_(id) {
   DCHECK(proxy_->IsImplThread());
   DidVisibilityChange(this, visible_);
   animation_registrar_->set_supports_scroll_animations(
       proxy_->SupportsImplScrolling());
 
   SetDebugState(settings.initial_debug_state);
 
   // LTHI always has an active tree.
   active_tree_ = LayerTreeImpl::create(this);
   TRACE_EVENT_OBJECT_CREATED_WITH_ID(
@@ skipping 952 matching lines @@
 
   DCHECK(resource_pool_);
   resource_pool_->CheckBusyResources();
   // Soft limit is used for resource pool such that memory returns to soft
   // limit after going over.
   resource_pool_->SetResourceUsageLimits(
       global_tile_state_.soft_memory_limit_in_bytes,
       unused_memory_limit_in_bytes,
       global_tile_state_.num_resources_limit);
 
-  // Staging pool resources are used as transfer buffers so we use
-  // |transfer_buffer_memory_limit_| as the memory limit for this resource pool.
+  // Release all staging resources when invisible.
   if (staging_resource_pool_) {
     staging_resource_pool_->CheckBusyResources();
     staging_resource_pool_->SetResourceUsageLimits(
-        visible_ ? transfer_buffer_memory_limit_ : 0,
-        transfer_buffer_memory_limit_,
-        std::numeric_limits<size_t>::max());
+        std::numeric_limits<size_t>::max(),
+        std::numeric_limits<size_t>::max(),
+        visible_ ? GetMaxStagingResourceCount() : 0);
   }
 
   DidModifyTilePriorities();
 }
 
 void LayerTreeHostImpl::DidModifyTilePriorities() {
   DCHECK(settings_.impl_side_painting);
   // Mark priorities as dirty and schedule a ManageTiles().
   tile_priorities_dirty_ = true;
   client_->SetNeedsManageTilesOnImplThread();
@@ skipping 697 matching lines @@
 }
 
 void LayerTreeHostImpl::CreateAndSetTileManager() {
   DCHECK(!tile_manager_);
   DCHECK(settings_.impl_side_painting);
   DCHECK(output_surface_);
   DCHECK(resource_provider_);
   DCHECK(proxy_->ImplThreadTaskRunner());
 
   ContextProvider* context_provider = output_surface_->context_provider();
-  transfer_buffer_memory_limit_ =
-      GetMaxTransferBufferUsageBytes(context_provider, settings_.refresh_rate);
-
   if (use_gpu_rasterization_ && context_provider) {
     resource_pool_ =
         ResourcePool::Create(resource_provider_.get(),
                              GL_TEXTURE_2D,
                              resource_provider_->best_texture_format());
 
     raster_worker_pool_ =
         GpuRasterWorkerPool::Create(proxy_->ImplThreadTaskRunner(),
                                     context_provider,
                                     resource_provider_.get());
@@ skipping 18 matching lines @@
     resource_pool_ = ResourcePool::Create(
         resource_provider_.get(),
         GL_TEXTURE_2D,
         resource_provider_->memory_efficient_texture_format());
 
     raster_worker_pool_ = PixelBufferRasterWorkerPool::Create(
         proxy_->ImplThreadTaskRunner(),
         RasterWorkerPool::GetTaskGraphRunner(),
         context_provider,
         resource_provider_.get(),
-        transfer_buffer_memory_limit_);
+        GetMaxTransferBufferUsageBytes(context_provider,
+                                       settings_.refresh_rate));
   } else {
     resource_pool_ =
         ResourcePool::Create(resource_provider_.get(),
                              GetMapImageTextureTarget(context_provider),
                              resource_provider_->best_texture_format());
 
     raster_worker_pool_ =
         ZeroCopyRasterWorkerPool::Create(proxy_->ImplThreadTaskRunner(),
                                          RasterWorkerPool::GetTaskGraphRunner(),
                                          resource_provider_.get());
@@ skipping 1365 matching lines @@
 }
 
 void LayerTreeHostImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
   std::vector<PictureLayerImpl*>::iterator it =
       std::find(picture_layers_.begin(), picture_layers_.end(), layer);
   DCHECK(it != picture_layers_.end());
   picture_layers_.erase(it);
 }
 
 }  // namespace cc