Replaced cc::SurfaceId::nonce_ with base::UnguessableToken

cc/surfaces/surface_id.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_SURFACES_SURFACE_ID_H_
 #define CC_SURFACES_SURFACE_ID_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <functional>
 
 #include "base/format_macros.h"
 #include "base/hash.h"
 #include "base/strings/stringprintf.h"
+#include "base/unguessable_token.h"
 
 namespace cc {
 
 class SurfaceId {
  public:
-  SurfaceId() : client_id_(0), local_id_(0), nonce_(0) {}
+  SurfaceId() : client_id_(0), local_id_(0), nonce_() {}

[Fady Samuel, 2016/09/30 20:30:41]

no need for calling the default constructor for nonce.

[Alex Z., 2016/10/05 18:10:45]

Done.

 
   SurfaceId(const SurfaceId& other)
       : client_id_(other.client_id_),
         local_id_(other.local_id_),
         nonce_(other.nonce_) {}
 
   // A SurfaceId consists of three components: client Id, local Id, and nonce.
   // A |client_id| is a display compositor service allocated ID that
   // uniquely identifies a client.
   // A |local_id| is a sequentially allocated ID generated by the display
   // 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)
+  SurfaceId(uint32_t client_id,
+            uint32_t local_id,
+            const base::UnguessableToken& nonce)
       : client_id_(client_id), local_id_(local_id), nonce_(nonce) {}
 
+  SurfaceId(uint32_t client_id, uint32_t local_id)
+      : client_id_(client_id), local_id_(local_id) {
+    nonce_ = base::UnguessableToken::Create();

[danakj, 2016/09/30 20:45:12]

do this as a constructor initializer

[Alex Z., 2016/10/05 18:10:45]

Done.

+  }
+
   bool is_null() const {
-    return client_id_ == 0 && nonce_ == 0 && local_id_ == 0;
+    return client_id_ == 0 && nonce_ == base::UnguessableToken() &&

[Fady Samuel, 2016/09/30 20:30:41]

nonce_.is_empty()

[Alex Z., 2016/10/05 18:10:45]

Done.

+           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_);
+    return base::HashInts(static_cast<uint64_t>(interim),

[danakj, 2016/09/30 20:45:12]

drop the static cast

[Alex Z., 2016/10/05 18:10:45]

Done.

+                          base::UnguessableTokenHash()(nonce_));
   }
 
   uint32_t client_id() const { return client_id_; }
 
   uint32_t local_id() const { return local_id_; }
 
-  uint64_t nonce() const { return nonce_; }
+  base::UnguessableToken nonce() const { return nonce_; }

[Fady Samuel, 2016/09/30 20:30:41]

const base::UnguessableToken&

[Alex Z., 2016/10/05 18:10:45]

Done.

 
   std::string ToString() const {
-    return base::StringPrintf("%d:%d:%" PRIu64, client_id_, local_id_, nonce_);
+    return base::StringPrintf("%d:%d" PRIu64, client_id_, local_id_)
+        .append(nonce_.ToString());

[danakj, 2016/09/30 20:45:11]

you need a space between fields tho. i'd rather you %s in the format and pass
ToString().c_str() to StringPrintf TBH

[Alex Z., 2016/10/05 18:10:45]

Done.

   }
 
   bool operator==(const SurfaceId& other) const {
     return client_id_ == other.client_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_);
   }
 
  private:
   // See SurfaceIdAllocator::GenerateId.
   uint32_t client_id_;
   uint32_t local_id_;
-  uint64_t nonce_;
+  base::UnguessableToken nonce_;
 };
 
 struct SurfaceIdHash {
   size_t operator()(const SurfaceId& key) const { return key.hash(); }
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_ID_H_