SetNeedsRedraw directly when updating a visible tile.

cc/test/fake_picture_pile.h

Index: cc/test/fake_picture_pile.h
diff --git a/cc/test/fake_picture_pile.h b/cc/test/fake_picture_pile.h
index e486e3b4cd37c63fb53bc38c13f6c9ababb83622..e7b619f1dcf8ab5bed022ca2057a278d479e0b70 100644
--- a/cc/test/fake_picture_pile.h
+++ b/cc/test/fake_picture_pile.h
@@ -7,12 +7,20 @@
 
 #include "cc/resources/picture_pile.h"
 
+namespace base {
+class WaitableEvent;
+}
+
 namespace cc {
 
 class FakePicturePile : public PicturePile {
  public:
+  FakePicturePile() : raster_thread_blocker_(nullptr) {}
   ~FakePicturePile() override {}
 
+  // PicturePile overrides.
+  scoped_refptr<RasterSource> CreateRasterSource() const override;
+
   using PicturePile::buffer_pixels;
   using PicturePile::CanRasterSlowTileCheck;
   using PicturePile::Clear;
@@ -37,6 +45,10 @@ class FakePicturePile : public PicturePile {
     has_any_recordings_ = has_recordings;
   }
 
+  void SetRasterThreadBlocker(base::WaitableEvent* blocker) {
+    raster_thread_blocker_ = blocker;
+  }
+
   TilingData& tiling() { return tiling_; }
 
   bool is_solid_color() const { return is_solid_color_; }
@@ -47,7 +59,11 @@ class FakePicturePile : public PicturePile {
   typedef PicturePile::PictureInfo PictureInfo;
   typedef PicturePile::PictureMapKey PictureMapKey;
   typedef PicturePile::PictureMap PictureMap;
+
+ private:
+  base::WaitableEvent* raster_thread_blocker_;

[reveman, 2014/11/13 20:50:58]

I don't think this code should be aware of raster threads or make the assumption
that playback might happen on a raster thread. Can you rename this and related
code to something like "playback_allowed_event_?

[danakj, 2014/11/13 21:24:40]

Hm, heh. I named it this thinking "it blocks the thread that does raster", which
is what it's doing, not so much about the concept of "raster threads". And the
playback /has/ to happen on a different thread or this test would deadlock when
it called Wait(). This is test code, is it really that important? I'll just
rename this to unblock me, but I don't see the point of this change I guess.

 };
+
 }  // namespace cc
 
 #endif  // CC_TEST_FAKE_PICTURE_PILE_H_