cc: Add LayerTreeHost::InitParams for LayerTreeHost creation.

cc/trees/layer_tree_host.h

 // Copyright 2011 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 CC_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <limits>
 #include <set>
 #include <string>
@@ skipping 53 matching lines @@
 class SharedBitmapManager;
 class TaskGraphRunner;
 class TopControlsManager;
 class UIResourceRequest;
 struct PendingPageScaleAnimation;
 struct RenderingStats;
 struct ScrollAndScaleSet;
 
 class CC_EXPORT LayerTreeHost {
  public:
+  struct InitParams {
+    LayerTreeHostClient* client = nullptr;
+    SharedBitmapManager* shared_bitmap_manager = nullptr;
+    gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager = nullptr;
+    TaskGraphRunner* task_graph_runner = nullptr;
+    LayerTreeSettings const* settings = nullptr;
+    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner;
+    mutable scoped_ptr<BeginFrameSource> external_begin_frame_source;

[danakj, 2015/05/06 21:00:48]

:( mutable.

this should be a movable type so we can pass/move it by value to LTH instead of
by const&, and then we don't need mutable here.

but in the absence of allowing std::move() how passing it as a (nonconst)
InitParams*, with a TODO to std::move() by value?

[sadrul, 2015/05/06 23:35:43]

Yep, makes sense. Done.

+
+    InitParams();
+    ~InitParams();
+  };
+
   // The SharedBitmapManager will be used on the compositor thread.
   static scoped_ptr<LayerTreeHost> CreateThreaded(
-      LayerTreeHostClient* client,
-      SharedBitmapManager* shared_bitmap_manager,
-      gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
-      TaskGraphRunner* task_graph_runner,
-      const LayerTreeSettings& settings,
-      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
-      scoped_ptr<BeginFrameSource> external_begin_frame_source);
+      const InitParams& params);
 
   static scoped_ptr<LayerTreeHost> CreateSingleThreaded(
-      LayerTreeHostClient* client,
       LayerTreeHostSingleThreadClient* single_thread_client,
-      SharedBitmapManager* shared_bitmap_manager,
-      gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
-      TaskGraphRunner* task_graph_runner,
-      const LayerTreeSettings& settings,
-      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
-      scoped_ptr<BeginFrameSource> external_begin_frame_source);
+      const InitParams& params);
   virtual ~LayerTreeHost();
 
   void SetLayerTreeHostClientReady();
 
   // LayerTreeHost interface to Proxy.
   void WillBeginMainFrame();
   void DidBeginMainFrame();
   void BeginMainFrame(const BeginFrameArgs& args);
   void BeginMainFrameNotExpectedSoon();
   void AnimateLayers(base::TimeTicks monotonic_frame_begin_time);
@@ skipping 202 matching lines @@
   void SendBeginFramesToChildren(const BeginFrameArgs& args) const;
 
   void SetAuthoritativeVSyncInterval(const base::TimeDelta& interval);
 
   PropertyTrees* property_trees() { return &property_trees_; }
   bool needs_meta_info_recomputation() {
     return needs_meta_info_recomputation_;
   }
 
  protected:
-  LayerTreeHost(LayerTreeHostClient* client,
-                SharedBitmapManager* shared_bitmap_manager,
-                gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
-                TaskGraphRunner* task_graph_runner,
-                const LayerTreeSettings& settings);
+  explicit LayerTreeHost(const InitParams& params);
   void InitializeThreaded(
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
   void InitializeSingleThreaded(
       LayerTreeHostSingleThreadClient* single_thread_client,
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
   void InitializeForTesting(scoped_ptr<Proxy> proxy_for_testing);
   void SetOutputSurfaceLostForTesting(bool is_lost) {
@@ skipping 128 matching lines @@
 
   uint32_t surface_id_namespace_;
   uint32_t next_surface_sequence_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_