SetNeedsRedraw directly when updating a visible tile.

cc/test/delayed_raster_picture_pile_impl.h

+// Copyright 2014 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_TEST_DELAYED_RASTER_PICTURE_PILE_IMPL_H_
+#define CC_TEST_DELAYED_RASTER_PICTURE_PILE_IMPL_H_
+
+#include "cc/resources/picture_pile_impl.h"
+
+namespace cc {
+
+class DelayedRasterTrigger;
+
+class DelayedRasterPicturePileImpl : public PicturePileImpl {

[reveman, 2014/11/10 23:43:01]

Did you consider adding this functionality to FakePicturePileImpl instead of
introducing a new class?

[danakj, 2014/11/12 20:19:39]

Done.

+ public:
+  static scoped_refptr<DelayedRasterPicturePileImpl> CreateFromOther(
+      PicturePileBase* other,
+      DelayedRasterTrigger* trigger) {
+    return new DelayedRasterPicturePileImpl(other, trigger);
+  }
+
+  // Hi-jack the PlaybackToCanvas method to delay its completion.
+  void PlaybackToCanvas(SkCanvas* canvas,
+                        const gfx::Rect& canvas_rect,
+                        float contents_scale) const override;
+
+ private:
+  DelayedRasterPicturePileImpl(PicturePileBase* other,
+                               DelayedRasterTrigger* trigger);
+  virtual ~DelayedRasterPicturePileImpl();

[reveman, 2014/11/10 23:43:01]

~DelayedRasterPicturePileImpl() override;

+
+  DelayedRasterTrigger* const trigger_;
+
+  DISALLOW_COPY_AND_ASSIGN(DelayedRasterPicturePileImpl);
+};
+
+}  // namespace cc
+
+#endif  // CC_TEST_DELAYED_RASTER_PICTURE_PILE_IMPL_H_