Expose Blimp dependencies to the embedder

blimp/client/core/compositor/blimp_compositor_dependencies.h

Index: blimp/client/core/compositor/blimp_compositor_dependencies.h
diff --git a/blimp/client/core/compositor/blimp_compositor_dependencies.h b/blimp/client/core/compositor/blimp_compositor_dependencies.h
new file mode 100644
index 0000000000000000000000000000000000000000..2a68562187109557abe1e3102d73d0a26554d715
--- /dev/null
+++ b/blimp/client/core/compositor/blimp_compositor_dependencies.h
@@ -0,0 +1,58 @@
+// 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.
+
+#ifndef BLIMP_CLIENT_CORE_COMPOSITOR_BLIMP_COMPOSITOR_DEPENDENCIES_H_
+#define BLIMP_CLIENT_CORE_COMPOSITOR_BLIMP_COMPOSITOR_DEPENDENCIES_H_
+
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+class Thread;
+}  // namespace base
+
+namespace cc {
+class ImageSerializationProcessor;
+class TaskGraphRunner;
+}
+
+namespace blimp {
+namespace client {
+
+class CompositorDependencies;
+
+// Holds all dependencies shared by BlimpCompositor instances.  This includes
+// shared threads and embedder dependencies.  Access to this will be shared
+// among all BlimpCompositors and should only be used on the main thread.
+class BlimpCompositorDependencies {
+ public:
+  explicit BlimpCompositorDependencies(
+      std::unique_ptr<CompositorDependencies> embedder_dependencies);
+  virtual ~BlimpCompositorDependencies();
+
+  // External compositor dependencies provided by the embedder.
+  CompositorDependencies* GetEmbedderDependencies();
+
+  // Threads shared by all BlimpCompositor instances.
+  cc::TaskGraphRunner* GetTaskGraphRunner();
+  scoped_refptr<base::SingleThreadTaskRunner> GetCompositorTaskRunner();
+
+  cc::ImageSerializationProcessor* GetImageSerializationProcessor();
+
+ private:
+  std::unique_ptr<CompositorDependencies> embedder_dependencies_;
+
+  // Shared threads/task runners that will be used by all BlimpCompositors.
+  std::unique_ptr<base::Thread> compositor_impl_thread_;
+  std::unique_ptr<cc::TaskGraphRunner> task_graph_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlimpCompositorDependencies);
+};
+
+}  // namespace client
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_CORE_COMPOSITOR_BLIMP_COMPOSITOR_DEPENDENCIES_H_