[blimp] Add SkPicture caching support.

cc/test/fake_engine_picture_cache.cc

+// 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 "cc/test/fake_engine_picture_cache.h"
+
+#include <map>
+#include <memory>
+
+#include "cc/blimp/picture_data.h"
+#include "cc/playback/display_item_list.h"
+#include "cc/test/picture_cache_model.h"
+#include "third_party/skia/include/core/SkPicture.h"
+
+namespace cc {
+
+FakeEnginePictureCache::FakeEnginePictureCache(PictureCacheModel* model)
+    : model_(model) {}
+
+FakeEnginePictureCache::~FakeEnginePictureCache() {}
+
+void FakeEnginePictureCache::MarkAllSkPicturesAsUsed(
+    const DisplayItemList* display_list) {
+  if (!display_list)
+    return;
+
+  for (auto it = display_list->begin(); it != display_list->end(); ++it) {
+    sk_sp<const SkPicture> picture = it->GetPicture();
+    if (!picture)
+      continue;
+
+    MarkUsed(picture.get());
+  }
+}
+
+const std::vector<uint32_t>& FakeEnginePictureCache::GetAllUsedPictureIds() {
+  return used_picture_ids_;
+}
+
+void FakeEnginePictureCache::MarkUsed(const SkPicture* picture) {
+  if (model_)
+    model_->AddPicture(picture);
+  used_picture_ids_.push_back(picture->uniqueID());
+}
+
+std::vector<PictureData>
+FakeEnginePictureCache::CalculateCacheUpdateAndFlush() {
+  return std::vector<PictureData>();
+}
+
+}  // namespace cc