cc: Clarify that color spaces are for raster

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 942d593868124b3593d8cd735d965cd939c8f069..e3fc2ccc0cc0d5f88d44856518ceab7d47a41357 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -964,11 +964,11 @@ void LayerTreeHost::SetPaintedDeviceScaleFactor(
   SetNeedsCommit();
 }
 
-void LayerTreeHost::SetDeviceColorSpace(
-    const gfx::ColorSpace& device_color_space) {
-  if (device_color_space_ == device_color_space)
+void LayerTreeHost::SetRasterColorSpace(
+    const gfx::ColorSpace& raster_color_space) {
+  if (raster_color_space_ == raster_color_space)
     return;
-  device_color_space_ = device_color_space;
+  raster_color_space_ = raster_color_space;
   LayerTreeHostCommon::CallFunctionForEveryLayer(
       this, [](Layer* layer) { layer->SetNeedsDisplay(); });
 }
@@ -1148,7 +1148,7 @@ void LayerTreeHost::PushPropertiesTo(LayerTreeImpl* tree_impl) {
 
   tree_impl->set_painted_device_scale_factor(painted_device_scale_factor_);
 
-  tree_impl->SetDeviceColorSpace(device_color_space_);
+  tree_impl->SetRasterColorSpace(raster_color_space_);
 
   tree_impl->set_content_source_id(content_source_id_);