Skip drawing unsupported layers in forced software mode

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 84c43c20b1c3462b342036d0fbbc7311e9249e28..7c9ebc51fc8499e4b85836b95f886eef1ca0689f 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -603,13 +603,19 @@ bool LayerTreeHostImpl::CalculateRenderPasses(FrameData* frame) {
     RenderPass* target_render_pass =
         frame->render_passes_by_id[target_render_pass_id];
 
+    AppendQuadsData append_quads_data(target_render_pass->id);
+
+    if (output_surface_->ForcedDrawToSoftwareDevice()) {
+      if (it->CanDrawInTilelessSoftwareMode()) {
+        append_quads_data.allow_tile_draw_quads = false;

[enne (OOO), 2013/05/30 17:04:37]

This line is a little weird.  Shouldn't allow_tile_draw_quads be set every time
ForcedDrawToSoftwareDevice is on and not just when you first encounter a layer
that can draw?

+      } else {
+        continue;
+      }
+    }
+
     bool prevent_occlusion = it.target_render_surface_layer()->HasCopyRequest();
     occlusion_tracker.EnterLayer(it, prevent_occlusion);
 
-    AppendQuadsData append_quads_data(target_render_pass->id);
-    if (output_surface_->ForcedDrawToSoftwareDevice())
-      append_quads_data.allow_tile_draw_quads = false;
-
     if (it.represents_target_render_surface()) {
       if (it->HasCopyRequest()) {
         have_copy_request = true;