WIP: Propagate SurfaceID up window tree hierarchy

cc/surfaces/surface_id.h

Index: cc/surfaces/surface_id.h
diff --git a/cc/surfaces/surface_id.h b/cc/surfaces/surface_id.h
index 48a434affe1309ba155534537d63b381d938bff8..8e76aa96bca50538f7fd9c4f3e9b75ad389fa07a 100644
--- a/cc/surfaces/surface_id.h
+++ b/cc/surfaces/surface_id.h
@@ -13,15 +13,16 @@
 #include "base/format_macros.h"
 #include "base/hash.h"
 #include "base/strings/stringprintf.h"
+#include "cc/surfaces/frame_sink_id.h"
 
 namespace cc {
 
 class SurfaceId {
  public:
-  SurfaceId() : client_id_(0), local_id_(0), nonce_(0) {}
+  SurfaceId() : local_id_(0), nonce_(0) {}
 
   SurfaceId(const SurfaceId& other)
-      : client_id_(other.client_id_),
+      : frame_sink_id_(other.frame_sink_id_),
         local_id_(other.local_id_),
         nonce_(other.nonce_) {}
 
@@ -32,43 +33,49 @@ class SurfaceId {
   // compositor client that uniquely identifies a surface.
   // A |nonce| is a cryptographically secure random int that makes a SurfaceId
   // unguessable by other clients.
-  SurfaceId(uint32_t client_id, uint32_t local_id, uint64_t nonce)
-      : client_id_(client_id), local_id_(local_id), nonce_(nonce) {}
+  SurfaceId(const FrameSinkId& frame_sink_id, uint32_t local_id, uint64_t nonce)
+      : frame_sink_id_(frame_sink_id), local_id_(local_id), nonce_(nonce) {}
 
   bool is_null() const {
-    return client_id_ == 0 && nonce_ == 0 && local_id_ == 0;
+    return frame_sink_id_.is_null() && nonce_ == 0 && local_id_ == 0;
   }
 
   size_t hash() const {
-    size_t interim = base::HashInts(client_id_, local_id_);
-    return base::HashInts(static_cast<uint64_t>(interim), nonce_);
+    size_t interim = base::HashInts(local_id_, nonce_);
+    return base::HashInts(frame_sink_id_.hash(), interim);
   }
 
-  uint32_t client_id() const { return client_id_; }
+  uint32_t client_id() const { return frame_sink_id_.client_id(); }
+
+  uint32_t sink_id() const { return frame_sink_id_.sink_id(); }
+
+  const FrameSinkId& frame_sink_id() const { return frame_sink_id_; }
 
   uint32_t local_id() const { return local_id_; }
 
   uint64_t nonce() const { return nonce_; }
 
   std::string ToString() const {
-    return base::StringPrintf("%d:%d:%" PRIu64, client_id_, local_id_, nonce_);
+    return base::StringPrintf("%s:LocalId(%d, %lu)" PRIu64,
+                              frame_sink_id_.ToString().c_str(), local_id_,
+                              nonce_);
   }
 
   bool operator==(const SurfaceId& other) const {
-    return client_id_ == other.client_id_ && local_id_ == other.local_id_ &&
-           nonce_ == other.nonce_;
+    return frame_sink_id_ == other.frame_sink_id_ &&
+           local_id_ == other.local_id_ && nonce_ == other.nonce_;
   }
 
   bool operator!=(const SurfaceId& other) const { return !(*this == other); }
 
   bool operator<(const SurfaceId& other) const {
-    return std::tie(client_id_, local_id_, nonce_) <
-           std::tie(other.client_id_, other.local_id_, other.nonce_);
+    return std::tie(frame_sink_id_, local_id_, nonce_) <
+           std::tie(frame_sink_id_, other.local_id_, other.nonce_);
   }
 
  private:
   // See SurfaceIdAllocator::GenerateId.
-  uint32_t client_id_;
+  FrameSinkId frame_sink_id_;
   uint32_t local_id_;
   uint64_t nonce_;
 };