SkColorType instead of (deprecated) SkBitmap::Config

cc/trees/layer_tree_host_pixeltest_readback.cc

Index: cc/trees/layer_tree_host_pixeltest_readback.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_readback.cc b/cc/trees/layer_tree_host_pixeltest_readback.cc
index e7845359dea29d7313041689fc49db32e3521aa3..e8ad466dfa72633c83b7b164a5239bc501ee9ba1 100644
--- a/cc/trees/layer_tree_host_pixeltest_readback.cc
+++ b/cc/trees/layer_tree_host_pixeltest_readback.cc
@@ -1109,15 +1109,10 @@ class LayerTreeHostReadbackViaCompositeAndReadbackPixelTest
       device_viewport_copy_rect.Intersect(device_viewport_copy_subrect_);
 
     scoped_ptr<SkBitmap> bitmap(new SkBitmap);
-    bitmap->setConfig(SkBitmap::kARGB_8888_Config,
-                      device_viewport_copy_rect.width(),
-                      device_viewport_copy_rect.height());
-    bitmap->allocPixels();
-    {
-      scoped_ptr<SkAutoLockPixels> lock(new SkAutoLockPixels(*bitmap));
-      layer_tree_host()->CompositeAndReadback(bitmap->getPixels(),
-                                              device_viewport_copy_rect);
-    }
+    bitmap->allocN32Pixels(device_viewport_copy_rect.width(),
+                           device_viewport_copy_rect.height());
+    layer_tree_host()->CompositeAndReadback(bitmap->getPixels(),
+                                            device_viewport_copy_rect);
 
     result_bitmap_ = bitmap.Pass();
     EndTest();