cc: turn on distance field text on animated layers

cc/layers/picture_layer_impl.cc

 // Copyright 2012 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.
 
 #include "cc/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 
@@ skipping 465 matching lines @@
 
   DCHECK(raster_page_scale_);
   DCHECK(raster_device_scale_);
   DCHECK(raster_source_scale_);
   DCHECK(raster_contents_scale_);
   DCHECK(low_res_raster_contents_scale_);
 
   was_screen_space_transform_animating_ =
       draw_properties().screen_space_transform_is_animating;
 
+  if (draw_transform_is_animating())
+    pile_->set_will_be_used_for_transform_animation(true);
+
   should_update_tile_priorities_ = true;
 
   UpdateTilePriorities(occlusion_in_content_space);
 }
 
 void PictureLayerImpl::UpdateTilePriorities(
     const Occlusion& occlusion_in_content_space) {
   DCHECK(!pile_->is_solid_color() || !tilings_->num_tilings());
 
   TRACE_EVENT0("cc", "PictureLayerImpl::UpdateTilePriorities");
@@ skipping 729 matching lines @@
   }
   if (tilings_->num_tilings() == 0)
     return;
 
   // We should only have one high res tiling.
   DCHECK_EQ(1, tilings_->NumHighResTilings());
 #endif
 }
 
 bool PictureLayerImpl::ShouldAdjustRasterScaleDuringScaleAnimations() const {
-  if (!layer_tree_impl()->use_gpu_rasterization())
-    return false;

[ajuma, 2014/10/17 13:36:24]

We still need this check, since we don't want to re-rasterize every frame when
using software rasterization.

-
-  // Re-rastering text at different scales using GPU rasterization causes
-  // texture uploads for glyphs at each scale (see crbug.com/366225). To
-  // workaround this performance issue, we don't re-rasterize layers with
-  // text during scale animations.
-  // TODO(ajuma): Remove this workaround once text can be efficiently
-  // re-rastered at different scales (e.g. by using distance-field fonts).
-  if (pile_->has_text())
-    return false;
-
   return true;
 }
 
 float PictureLayerImpl::MaximumTilingContentsScale() const {
   float max_contents_scale = MinimumContentsScale();
   for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
     const PictureLayerTiling* tiling = tilings_->tiling_at(i);
     max_contents_scale = std::max(max_contents_scale, tiling->contents_scale());
   }
   return max_contents_scale;
@@ skipping 413 matching lines @@
       PictureLayerTilingSet::TilingRange tiling_range = CurrentTilingRange();
       size_t current_tiling_range_offset = current_tiling_ - tiling_range.start;
       return tiling_range.end - 1 - current_tiling_range_offset;
     }
   }
   NOTREACHED();
   return 0;
 }
 
 }  // namespace cc