Paint low-res tiles without expensive filters.

cc/tile_manager.cc

Index: cc/tile_manager.cc
diff --git a/cc/tile_manager.cc b/cc/tile_manager.cc
index 2f95204abb10d66a3e687ff9baf1a97f2f65ba8b..c2645522594a5317702c182562fe1a5e4b30a6e4 100644
--- a/cc/tile_manager.cc
+++ b/cc/tile_manager.cc
@@ -15,6 +15,7 @@
 #include "cc/raster_worker_pool.h"
 #include "cc/resource_pool.h"
 #include "cc/tile.h"
+#include "skia/ext/paint_simplifier.h"
 #include "third_party/skia/include/core/SkDevice.h"
 
 namespace cc {
@@ -72,6 +73,7 @@ std::string ValueToString(scoped_ptr<base::Value> value)
   return str;
 }
 
+
 }  // namespace
 
 scoped_ptr<base::Value> TileManagerBinAsValue(TileManagerBin bin) {
@@ -664,7 +666,8 @@ void TileManager::DispatchOneRasterTask(scoped_refptr<Tile> tile) {
                      resource_id),
                  tile->content_rect_,
                  tile->contents_scale(),
-                 use_cheapness_estimator_),
+                 use_cheapness_estimator_,
+                 ShouldSimplifyPaint(tile.get())),
       base::Bind(&TileManager::OnRasterTaskCompleted,
                  base::Unretained(this),
                  tile,
@@ -681,6 +684,7 @@ void TileManager::PerformOneRaster(Tile* tile) {
                 tile->content_rect_,
                 tile->contents_scale(),
                 use_cheapness_estimator_,
+                ShouldSimplifyPaint(tile),
                 tile->picture_pile(),
                 &rendering_stats_);
 
@@ -786,6 +790,7 @@ void TileManager::PerformRaster(uint8* buffer,
                                 const gfx::Rect& rect,
                                 float contents_scale,
                                 bool use_cheapness_estimator,
+                                bool simplify_paint,
                                 PicturePileImpl* picture_pile,
                                 RenderingStats* stats) {
   TRACE_EVENT0("cc", "TileManager::PerformRaster");
@@ -801,6 +806,13 @@ void TileManager::PerformRaster(uint8* buffer,
   if (stats)
     begin_time = base::TimeTicks::Now();
 
+  // FIXME: PerformRaster is a static function, so we can't just create
+  // one in the constructor and reuse it. But the object is refcounted
+  // so may not be happy living on the stack. How do we get rid of this
+  // new?

[Sami, 2013/02/08 13:44:01]

You could create the simplifier as a member of TileManager and pass the
reference to this function.

+  if (simplify_paint)
+    canvas.setDrawFilter(new skia::PaintSimplifier);
+
   int64 total_pixels_rasterized = 0;
   picture_pile->Raster(&canvas, rect, contents_scale,
                        &total_pixels_rasterized);
@@ -852,4 +864,15 @@ void TileManager::RunImageDecodeTask(skia::LazyPixelRef* pixel_ref,
   }
 }
 
+// Needs to be a member of TileManager to access Tile::managed_state()
+bool TileManager::ShouldSimplifyPaint(Tile* tile) {
+  // FIXME: tree_priority can remain SMOOTHNESS_TAKES_PRIORITY an arbitrary
+  // length of time after a fling ends. resolution can be LOW_RESOLUTION
+  // at times other than mid-fling. The two only seem to be true
+  // together during flings & pinch-zooms.
+  return
+    GlobalState().tree_priority == SMOOTHNESS_TAKES_PRIORITY &&
+    tile->managed_state().resolution == LOW_RESOLUTION;
+}
+
 }  // namespace cc