SetNeedsRedraw directly when updating a visible tile.

cc/resources/tile_manager.h

Index: cc/resources/tile_manager.h
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index f5bea383141a38c325f695ed2247e9b7561331a9..2a04425047fe1884b74e1a838b1550b2a9f4c352 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -104,8 +104,11 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   void ManageTiles(const GlobalStateThatImpactsTilePriority& state);
 
-  // Returns true when visible tiles have been initialized.
-  bool UpdateVisibleTiles();
+  void UpdateVisibleTiles();
+
+  bool has_active_visible_tile_scheduled() {

[reveman, 2014/10/30 19:37:42]

I think this is too implementation specific. For example, it will return very
different results depending on the value of scheduled_raster_task_limit_. I'm
also worried that exposing implementation specific details such as this will
create friction when trying to make changes to the tile manager.

Something like IsTopPriorityUninitializedTileVisibleAndOnActiveTree() would be
better as it's well defined. Not sure you need to reach into the tile manager to
answer that though.

[danakj, 2014/10/30 19:49:07]

And I think that all of those results would be acceptable for our uses.
We just need a signal that there's some work being that would be visible. I
didn't write any tests that tie this into being very specific. The test I added
is causing some tiles at a new scale to be created and trying to draw until they
are done. That's the use case we care about, and as long as we satisfy that, we
can change the signal that the tile manager gives out as much as we like.
I think it has to come from the tile manager, cuz it needs to know what tiles
the raster iterators are going to spit out, which is generated from the tile
manager.

I agree IsTopPriorityUninitializedTileVisibleAndOnActiveTree would probably be
enough. It should be for the test case I've written, so I'll try that out.
Thanks!

+    return has_active_visible_tile_scheduled_;
+  }
 
   scoped_refptr<Tile> CreateTile(RasterSource* raster_source,
                                  const gfx::Size& tile_size,
@@ -248,9 +251,9 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   RenderingStatsInstrumentation* rendering_stats_instrumentation_;
 
-  bool did_initialize_visible_tile_;
   bool did_check_for_completed_tasks_since_last_schedule_tasks_;
   bool did_oom_on_last_assign_;
+  bool has_active_visible_tile_scheduled_;
 
   typedef base::hash_map<uint32_t, scoped_refptr<ImageDecodeTask>>
       PixelRefTaskMap;