Sky shouldn't crash on device rotate

sky/compositor/texture_cache.cc

+// Copyright 2015 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 "sky/compositor/texture_cache.h"
+
+#include "mojo/converters/geometry/geometry_type_converters.h"
+#include "mojo/gpu/gl_texture.h"
+
+namespace sky {
+
+TextureCache::TextureCache() {
+}
+
+TextureCache::~TextureCache() {
+}
+
+scoped_ptr<mojo::GLTexture> TextureCache::GetTexture(const gfx::Size& size) {
+  if (size != size_) {
+    available_textures_.clear();
+    size_ = size;
+  }
+  if (available_textures_.empty())
+    return nullptr;
+  scoped_ptr<mojo::GLTexture> texture(available_textures_.back());
+  available_textures_.back() = nullptr;
+  available_textures_.pop_back();
+  return texture.Pass();
+}
+
+void TextureCache::PutTexture(scoped_ptr<mojo::GLTexture> texture) {
+  if (texture->size() != size_)
+    return;
+  available_textures_.push_back(texture.release());
+}
+
+}  // namespace sky