Move logic from ImageTransportSurfaceOverlayMac into ui/

ui/accelerated_widget_mac/ca_layer_tree_host.mm

Index: ui/accelerated_widget_mac/ca_layer_tree_host.mm
diff --git a/ui/accelerated_widget_mac/ca_layer_tree_host.mm b/ui/accelerated_widget_mac/ca_layer_tree_host.mm
new file mode 100644
index 0000000000000000000000000000000000000000..bd390fde84ea3fe6278d6d1036b03e601feb5fb8
--- /dev/null
+++ b/ui/accelerated_widget_mac/ca_layer_tree_host.mm
@@ -0,0 +1,88 @@
+// Copyright 2016 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 "ui/accelerated_widget_mac/ca_layer_tree_host.h"
+
+#include "base/trace_event/trace_event.h"
+#include "ui/base/cocoa/animation_utils.h"
+
+namespace ui {
+
+CALayerTreeHost::CALayerTreeHost(bool allow_remote_layers)
+    : allow_remote_layers_(allow_remote_layers) {
+  if (allow_remote_layers_) {
+    root_ca_layer_.reset([[CALayer alloc] init]);
+    [root_ca_layer_ setGeometryFlipped:YES];
+    [root_ca_layer_ setOpaque:YES];
+  }
+}
+
+CALayerTreeHost::~CALayerTreeHost() {}
+
+void CALayerTreeHost::Resize(const gfx::Size& pixel_size, float scale_factor) {
+  pixel_size_ = pixel_size;
+  scale_factor_ = scale_factor;
+}
+
+bool CALayerTreeHost::SetPendingBackbuffer(
+    base::ScopedCFTypeRef<IOSurfaceRef> backbuffer) {
+  if (pending_ca_layer_tree_) {
+    DLOG(ERROR) << "Either CALayer overlays or a backbuffer should be "
+                   "specified, but not both.";
+    return false;
+  }
+  if (pending_partial_damage_tree_) {
+    DLOG(ERROR) << "Only one backbuffer per swap is allowed.";
+    return false;
+  }
+  pending_partial_damage_tree_.reset(new CALayerPartialDamageTree(
+      allow_remote_layers_, backbuffer, gfx::Rect(pixel_size_)));
+
+  return true;
+}
+
+CALayerTree* CALayerTreeHost::GetPendingCALayerTree() {
+  if (pending_partial_damage_tree_) {
+    DLOG(ERROR) << "Either CALayer overlays or a backbuffer should be "
+                   "specified, but not both.";
+  }
+  if (!pending_ca_layer_tree_)
+    pending_ca_layer_tree_.reset(new CALayerTree);
+  return pending_ca_layer_tree_.get();
+}
+
+void CALayerTreeHost::CommitPendingTreesToCA(
+    const gfx::Rect& pixel_damage_rect) {
+  // Update the CALayer hierarchy.
+  ScopedCAActionDisabler disabler;
+  if (pending_ca_layer_tree_) {
+    pending_ca_layer_tree_->CommitScheduledCALayers(
+        root_ca_layer_.get(), std::move(current_ca_layer_tree_), scale_factor_);
+    current_ca_layer_tree_.swap(pending_ca_layer_tree_);
+    current_partial_damage_tree_.reset();
+  } else if (pending_partial_damage_tree_) {
+    pending_partial_damage_tree_->CommitCALayers(
+        root_ca_layer_.get(), std::move(current_partial_damage_tree_),
+        scale_factor_, pixel_damage_rect);
+    current_partial_damage_tree_.swap(pending_partial_damage_tree_);
+    current_ca_layer_tree_.reset();
+  } else {
+    TRACE_EVENT0("gpu", "Blank frame: No overlays or CALayers");
+    [root_ca_layer_ setSublayers:nil];
+    current_partial_damage_tree_.reset();
+    current_ca_layer_tree_.reset();
+  }
+
+  // Reset all state for the next frame.
+  pending_ca_layer_tree_.reset();
+  pending_partial_damage_tree_.reset();
+}
+
+IOSurfaceRef CALayerTreeHost::GetFrontbufferIOSurface() {
+  if (!current_partial_damage_tree_)
+    return nullptr;
+  return current_partial_damage_tree_->RootLayerIOSurface();
+}
+
+}  // namespace ui