exo: Add support for alpha_compositing interface to wayland bindings.

ui/compositor/layer.cc

 // Copyright (c) 2012 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/compositor/layer.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
@@ skipping 548 matching lines @@
 void Layer::SetTextureFlipped(bool flipped) {
   DCHECK(texture_layer_.get());
   texture_layer_->SetFlipped(flipped);
 }
 
 bool Layer::TextureFlipped() const {
   DCHECK(texture_layer_.get());
   return texture_layer_->flipped();
 }
 
+void Layer::SetTextureAlpha(float alpha) {
+  DCHECK(texture_layer_.get());
+  texture_layer_->SetVertexOpacity(alpha, alpha, alpha, alpha);
+}
+
 void Layer::SetShowSurface(
     cc::SurfaceId surface_id,
     const cc::SurfaceLayer::SatisfyCallback& satisfy_callback,
     const cc::SurfaceLayer::RequireCallback& require_callback,
     gfx::Size surface_size,
     float scale,
     gfx::Size frame_size_in_dip) {
   DCHECK(type_ == LAYER_TEXTURED || type_ == LAYER_SOLID_COLOR);
 
   scoped_refptr<cc::SurfaceLayer> new_layer =
@@ skipping 437 matching lines @@
   if (animator_) {
     animator_->ResetCompositor(compositor);
     animator_->RemoveFromCollection(collection);
   }
 
   for (auto* child : children_)
     child->ResetCompositorForAnimatorsInTree(compositor);
 }
 
 }  // namespace ui