Added preliminary support for tile rasterization with Ganesh

cc/resources/ganesh_rasterizer.h

+// Copyright 2013 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_RESOURCES_GANESH_RASTERIZER_H_
+#define CC_RESOURCES_GANESH_RASTERIZER_H_
+
+#include "base/memory/scoped_vector.h"
+#include "cc/resources/resource_pool.h"
+#include "cc/resources/tile.h"
+
+namespace cc {
+
+class ContextProvider;
+class ResourceProvider;
+class RenderingStatsInstrumentation;
+
+class CC_EXPORT GaneshRasterizerClient {
+ public:
+  virtual void OnGaneshRasterTaskCompleted(
+      Tile* tile, scoped_ptr<ResourcePool::Resource> resource,
+      bool was_canceled) = 0;

[reveman, 2013/11/24 21:56:57]

why "was_canceled"? I don't see why that would ever be true as we run these
tasks synchronously. am I missing something?

[slavi, 2013/11/25 23:13:14]

You're not. I modeled this after the other RasterWorkingPools which do have
was_canceled and I wanted to reuse that to signal a GL error or similar failure
to produce a tile. Although currently that's a TODO in my list, not really
expressed in the code.

+};
+
+class CC_EXPORT GaneshRasterizer {
+ public:
+  static scoped_ptr<GaneshRasterizer> Create(
+      ContextProvider* context_provider,
+      ResourceProvider* resource_provider);
+  ~GaneshRasterizer();
+
+  void SetClient(GaneshRasterizerClient* client);
+
+  ResourceFormat GetResourceFormat() const { return BGRA_8888; }

[reveman, 2013/11/24 21:56:57]

This will be a problem after you rebase this patch as the ResourcePool will only
use one resource format. Ideally we would be able to use the same format for
better reuse of resources.

[slavi, 2013/11/25 23:13:14]

See the current way where in the rasterizer I read the format from the resource
that was passed. The format of the resources we're creating currently is being
read from the raster_worker_pool. I'm not certain how we should choose the best
format in hybrid settings where we have several rasterizers active. Maybe we
should support multiple resource formats in the same time? Or maybe we can
ignore it for now?

+
+  void PushRasterTask(Tile* tile, scoped_ptr<ResourcePool::Resource> resource);
+  void FlushRasterTasks(
+      RenderingStatsInstrumentation* rendering_stats_instrumentation);

[reveman, 2013/11/24 21:56:57]

Instead of push/flush, what if we add a container (much like
RasterWorkerPool::RasterTask::Queue) and just pass this container to a
RunRasterTasks function?

Seems like that would also remove the need for the GaneshRasterizerClient
interface.

+
+ private:
+  GaneshRasterizer(
+      ContextProvider* context_provider,
+      ResourceProvider* resource_provider);
+
+  struct RasterTask {
+    RasterTask(Tile* tile, scoped_ptr<ResourcePool::Resource> resource);
+    ~RasterTask();
+
+    Tile* tile_;
+    scoped_ptr<ResourcePool::Resource> resource_;
+  };
+  typedef ScopedVector<RasterTask> RasterTaskVector;
+
+  GaneshRasterizerClient* client_;
+  ContextProvider* context_provider_;
+  ResourceProvider* resource_provider_;
+  RasterTaskVector raster_tasks_;
+};
+
+}   // namespace cc
+
+#endif  // CC_RESOURCES_GANESH_RASTERIZER_H_