Allow one-copy task tile worker pool to use compressed textures.

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index b057366d8561d0160dcc7e544406f316a363a514..c5f8190dbf4c5cba5abc97d76b342c7e23ee7b7a 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -141,8 +141,10 @@ Compositor::Compositor(ui::ContextFactory* context_factory,
       command_line->HasSwitch(cc::switches::kEnableCompositorPropertyTrees);
   settings.use_zero_copy = IsUIZeroCopyEnabled();
 
-  settings.renderer_settings.use_rgba_4444_textures =
-      command_line->HasSwitch(switches::kUIEnableRGBA4444Textures);
+   settings.renderer_settings.memory_efficient_format =
+      settings.renderer_settings.memory_efficient_format_with_alpha =
+          command_line->HasSwitch(switches::kUIEnableRGBA4444Textures) ?
+              cc::RGBA_4444 : cc::RGBA_8888;
 
   // UI compositor always uses partial raster if not using zero-copy. Zero copy
   // doesn't currently support partial raster.