CC: Tile-size cleanup.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 37c83289700ab9fef4cd1fb356d0f9c354d29b0f..ea431388fc78dc56265938d37189900e192321b4 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -675,17 +675,21 @@ gfx::Size PictureLayerImpl::CalculateTileSize(
   }
 
   gfx::Size default_tile_size = layer_tree_impl()->settings().default_tile_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()) {
-    // 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);
+    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));
 
-  gfx::Size max_untiled_content_size =
-      layer_tree_impl()->settings().max_untiled_layer_size;
+  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));