Remove CompositeAndReadback from LayerTreeHost(Impl) and the Proxys.

cc/trees/single_thread_proxy.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/single_thread_proxy.h"
 
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/output/context_provider.h"
@@ skipping 37 matching lines @@
   layer_tree_host_impl_ = layer_tree_host_->CreateLayerTreeHostImpl(this);
 }
 
 SingleThreadProxy::~SingleThreadProxy() {
   TRACE_EVENT0("cc", "SingleThreadProxy::~SingleThreadProxy");
   DCHECK(Proxy::IsMainThread());
   // Make sure Stop() got called or never Started.
   DCHECK(!layer_tree_host_impl_);
 }
 
-bool SingleThreadProxy::CompositeAndReadback(void* pixels,
-                                             const gfx::Rect& rect) {
-  TRACE_EVENT0("cc", "SingleThreadProxy::CompositeAndReadback");
-  DCHECK(Proxy::IsMainThread());
-
-  gfx::Rect device_viewport_damage_rect = rect;
-
-  LayerTreeHostImpl::FrameData frame;
-  if (!CommitAndComposite(gfx::FrameTime::Now(),
-                          device_viewport_damage_rect,
-                          true,  // for_readback
-                          &frame))
-    return false;
-
-  {
-    DebugScopedSetImplThread impl(this);
-    layer_tree_host_impl_->Readback(pixels, rect);
-
-    if (layer_tree_host_impl_->IsContextLost())
-      return false;
-  }
-
-  return true;
-}
-
 void SingleThreadProxy::FinishAllRendering() {
   TRACE_EVENT0("cc", "SingleThreadProxy::FinishAllRendering");
   DCHECK(Proxy::IsMainThread());
   {
     DebugScopedSetImplThread impl(this);
     layer_tree_host_impl_->FinishAllRendering();
   }
 }
 
 bool SingleThreadProxy::IsStarted() const {
@@ skipping 263 matching lines @@
 
 void SingleThreadProxy::DidSwapBuffersCompleteOnImplThread() {
   TRACE_EVENT0("cc", "SingleThreadProxy::DidSwapBuffersCompleteOnImplThread");
   client_->DidCompleteSwapBuffers();
 }
 
 // Called by the legacy scheduling path (e.g. where render_widget does the
 // scheduling)
 void SingleThreadProxy::CompositeImmediately(base::TimeTicks frame_begin_time) {
   TRACE_EVENT0("cc", "SingleThreadProxy::CompositeImmediately");
-  gfx::Rect device_viewport_damage_rect;
 
   LayerTreeHostImpl::FrameData frame;
-  if (CommitAndComposite(frame_begin_time,
-                         device_viewport_damage_rect,
-                         false,  // for_readback
-                         &frame)) {
+  if (CommitAndComposite(frame_begin_time, &frame)) {
     {
       DebugScopedSetMainThreadBlocked main_thread_blocked(this);
       DebugScopedSetImplThread impl(this);
 
       // This CapturePostTasks should be destroyed before
       // DidCommitAndDrawFrame() is called since that goes out to the embedder,
       // and we want the embedder to receive its callbacks before that.
       // NOTE: This maintains consistent ordering with the ThreadProxy since
       // the DidCommitAndDrawFrame() must be post-tasked from the impl thread
       // there as the main thread is not blocked, so any posted tasks inside
@@ skipping 25 matching lines @@
     DebugScopedSetImplThread impl(this);
     if (layer_tree_host_impl_->renderer()) {
       DCHECK(!layer_tree_host_->output_surface_lost());
       layer_tree_host_impl_->renderer()->DoNoOp();
     }
   }
 }
 
 bool SingleThreadProxy::CommitAndComposite(
     base::TimeTicks frame_begin_time,
-    const gfx::Rect& device_viewport_damage_rect,
-    bool for_readback,
     LayerTreeHostImpl::FrameData* frame) {
   TRACE_EVENT0("cc", "SingleThreadProxy::CommitAndComposite");
   DCHECK(Proxy::IsMainThread());
 
   if (!layer_tree_host_->InitializeOutputSurfaceIfNeeded())
     return false;
 
   layer_tree_host_->AnimateLayers(frame_begin_time);
 
   if (PrioritizedResourceManager* contents_texture_manager =
       layer_tree_host_->contents_texture_manager()) {
     contents_texture_manager->UnlinkAndClearEvictedBackings();
     contents_texture_manager->SetMaxMemoryLimitBytes(
         layer_tree_host_impl_->memory_allocation_limit_bytes());
     contents_texture_manager->SetExternalPriorityCutoff(
         layer_tree_host_impl_->memory_allocation_priority_cutoff());
   }
 
   scoped_ptr<ResourceUpdateQueue> queue =
       make_scoped_ptr(new ResourceUpdateQueue);
   layer_tree_host_->UpdateLayers(queue.get());
 
   layer_tree_host_->WillCommit();
 
   DoCommit(queue.Pass());
-  bool result = DoComposite(
-      frame_begin_time, device_viewport_damage_rect, for_readback, frame);
+  bool result = DoComposite(frame_begin_time, frame);
   layer_tree_host_->DidBeginMainFrame();
   return result;
 }
 
 bool SingleThreadProxy::ShouldComposite() const {
   DCHECK(Proxy::IsImplThread());
   return layer_tree_host_impl_->visible() &&
          layer_tree_host_impl_->CanDraw();
 }
 
 void SingleThreadProxy::UpdateBackgroundAnimateTicking() {
   DCHECK(Proxy::IsImplThread());
   layer_tree_host_impl_->UpdateBackgroundAnimateTicking(
       !ShouldComposite() && layer_tree_host_impl_->active_tree()->root_layer());
 }
 
 bool SingleThreadProxy::DoComposite(
     base::TimeTicks frame_begin_time,
-    const gfx::Rect& device_viewport_damage_rect,
-    bool for_readback,
     LayerTreeHostImpl::FrameData* frame) {
   TRACE_EVENT0("cc", "SingleThreadProxy::DoComposite");
   DCHECK(!layer_tree_host_->output_surface_lost());
 
   bool lost_output_surface = false;
   {
     DebugScopedSetImplThread impl(this);
     base::AutoReset<bool> mark_inside(&inside_draw_, true);
 
-    bool can_do_readback = layer_tree_host_impl_->renderer()->CanReadPixels();
-
     // We guard PrepareToDraw() with CanDraw() because it always returns a valid
     // frame, so can only be used when such a frame is possible. Since
     // DrawLayers() depends on the result of PrepareToDraw(), it is guarded on
     // CanDraw() as well.
-    if (!ShouldComposite() || (for_readback && !can_do_readback)) {
+    if (!ShouldComposite()) {
       UpdateBackgroundAnimateTicking();
       return false;
     }
 
     layer_tree_host_impl_->Animate(
         layer_tree_host_impl_->CurrentFrameTimeTicks());
     UpdateBackgroundAnimateTicking();
 
     if (!layer_tree_host_impl_->IsContextLost()) {
-      layer_tree_host_impl_->PrepareToDraw(frame, device_viewport_damage_rect);
+      layer_tree_host_impl_->PrepareToDraw(frame);
       layer_tree_host_impl_->DrawLayers(frame, frame_begin_time);
       layer_tree_host_impl_->DidDrawAllLayers(*frame);
     }
     lost_output_surface = layer_tree_host_impl_->IsContextLost();
 
     bool start_ready_animations = true;
     layer_tree_host_impl_->UpdateAnimationState(start_ready_animations);
 
     layer_tree_host_impl_->ResetCurrentFrameTimeForNextFrame();
   }
 
   if (lost_output_surface) {
     layer_tree_host_->DidLoseOutputSurface();
     return false;
   }
 
   return true;
 }
 
 void SingleThreadProxy::DidSwapFrame() {
   if (next_frame_is_newly_committed_frame_) {
     next_frame_is_newly_committed_frame_ = false;
     layer_tree_host_->DidCommitAndDrawFrame();
   }
 }
 
 bool SingleThreadProxy::CommitPendingForTesting() { return false; }
 
 }  // namespace cc