Replace source pointer in cc::CopyOutputRequest with a base::UnguessableToken

cc/layers/layer.cc

Index: cc/layers/layer.cc
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index e878a2020fb46732a3fd02938e91947f1fb818ab..46e6c34042e2bd23809c16ced74076d99159ad73 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -355,11 +355,12 @@ bool Layer::HasAncestor(const Layer* ancestor) const {
 
 void Layer::RequestCopyOfOutput(std::unique_ptr<CopyOutputRequest> request) {
   DCHECK(IsPropertyChangeAllowed());
-  if (void* source = request->source()) {
+  if (request->has_source()) {
+    auto source = request->source();

[Fady Samuel, 2017/01/26 21:49:34]

const base::UnguessableToken& instead of auto?

[Saman Sami, 2017/01/26 22:23:22]

Done.

     auto it =
         std::find_if(inputs_.copy_requests.begin(), inputs_.copy_requests.end(),
                      [source](const std::unique_ptr<CopyOutputRequest>& x) {
-                       return x->source() == source;
+                       return x->has_source() && x->source() == source;
                      });
     if (it != inputs_.copy_requests.end())
       inputs_.copy_requests.erase(it);