CC: Tile-size cleanup.

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 657 matching lines @@
   if (pile_->is_mask()) {
     // Masks are not tiled, so if we can't cover the whole mask with one tile,
     // don't make any tiles at all. Returning an empty size signals this.
     if (content_bounds.width() > max_texture_size ||
         content_bounds.height() > max_texture_size)
       return gfx::Size();
     return content_bounds;
   }
 
   gfx::Size default_tile_size = layer_tree_impl()->settings().default_tile_size;
-  if (layer_tree_impl()->use_gpu_rasterization()) {
-    // TODO(ernstm) crbug.com/365877: We need a unified way to override the
-    // default-tile-size.
-    default_tile_size =
-        gfx::Size(layer_tree_impl()->device_viewport_size().width(),
-                  layer_tree_impl()->device_viewport_size().height() / 4);
-  }
-  default_tile_size.SetToMin(gfx::Size(max_texture_size, max_texture_size));
-
   gfx::Size max_untiled_content_size =
       layer_tree_impl()->settings().max_untiled_layer_size;
+
+  // For GPU rasterization, we pick an ideal tile size using the viewport,
+  // so we don't need the above settings.
+  if (layer_tree_impl()->use_gpu_rasterization()) {
+    int width = layer_tree_impl()->device_viewport_size().width();
+    int height = layer_tree_impl()->device_viewport_size().height() / 4;

[vmpstr, 2014/10/07 17:49:47]

Can you do something like std::min(1,
layer_tree_impl()->device_viewport_size().height() / 4) here? Or maybe (...) +
1;? Or am I worried too much about viewport size being 3 pixels tall?

[ernstm, 2014/10/07 18:17:31]

How about rounding up: ((...)+3)/4.

+    default_tile_size = gfx::Size(width, height);
+    // Since the width is already expanded to viewport width, we use
+    // double the height as our max untiled size.
+    max_untiled_content_size = gfx::Size(height, height);

[ernstm, 2014/10/07 18:17:31]

This sets the max_untiled_content_size to height^2, but the comment above says
something else?

+  }
+
+  default_tile_size.SetToMin(gfx::Size(max_texture_size, max_texture_size));
   max_untiled_content_size.SetToMin(
       gfx::Size(max_texture_size, max_texture_size));
 
   bool any_dimension_too_large =
       content_bounds.width() > max_untiled_content_size.width() ||
       content_bounds.height() > max_untiled_content_size.height();
 
   bool any_dimension_one_tile =
       content_bounds.width() <= default_tile_size.width() ||
       content_bounds.height() <= default_tile_size.height();
@@ skipping 1088 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