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

cc/layers/surface_layer_unittest.cc

Index: cc/layers/surface_layer_unittest.cc
diff --git a/cc/layers/surface_layer_unittest.cc b/cc/layers/surface_layer_unittest.cc
index 5b688676e02ccd34764232b9f6f1f5e0bc052fec..1cbb41003bffd79a9fad3a7a31a2055e5b9980df 100644
--- a/cc/layers/surface_layer_unittest.cc
+++ b/cc/layers/surface_layer_unittest.cc
@@ -69,8 +69,6 @@
 // Check that one surface can be referenced by multiple LayerTreeHosts, and
 // each will create its own SurfaceSequence that's satisfied on destruction.
 TEST_F(SurfaceLayerTest, MultipleFramesOneSurface) {
-  const base::UnguessableToken kArbitraryToken =
-      base::UnguessableToken::Create();
   SurfaceSequence blank_change;  // Receives sequence if commit doesn't happen.
 
   SurfaceId required_id;
@@ -78,9 +76,8 @@
   scoped_refptr<SurfaceLayer> layer(SurfaceLayer::Create(
       base::Bind(&SatisfyCallback, &blank_change),
       base::Bind(&RequireCallback, &required_id, &required_seq)));
-  layer->SetSurfaceId(
-      SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, kArbitraryToken)), 1.f,
-      gfx::Size(1, 1));
+  layer->SetSurfaceId(SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, 0)), 1.f,
+                      gfx::Size(1, 1));
   layer_tree_host_->GetSurfaceSequenceGenerator()->set_frame_sink_id(
       FrameSinkId(1, 1));
   layer_tree_->SetRootLayer(layer);
@@ -92,9 +89,8 @@
   scoped_refptr<SurfaceLayer> layer2(SurfaceLayer::Create(
       base::Bind(&SatisfyCallback, &blank_change),
       base::Bind(&RequireCallback, &required_id, &required_seq)));
-  layer2->SetSurfaceId(
-      SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, kArbitraryToken)), 1.f,
-      gfx::Size(1, 1));
+  layer2->SetSurfaceId(SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, 0)),
+                       1.f, gfx::Size(1, 1));
   layer_tree_host2->GetSurfaceSequenceGenerator()->set_frame_sink_id(
       FrameSinkId(2, 2));
   layer_tree_host2->SetRootLayer(layer2);
@@ -115,8 +111,8 @@
 
   // Set of sequences that need to be satisfied should include sequences from
   // both trees.
-  EXPECT_TRUE(required_id == SurfaceId(kArbitraryFrameSinkId,
-                                       LocalFrameId(1, kArbitraryToken)));
+  EXPECT_TRUE(required_id ==
+              SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, 0)));
   EXPECT_EQ(2u, required_seq.size());
   EXPECT_TRUE(required_seq.count(expected1));
   EXPECT_TRUE(required_seq.count(expected2));
@@ -145,9 +141,8 @@
     layer_ = SurfaceLayer::Create(
         base::Bind(&SatisfyCallback, &satisfied_sequence_),
         base::Bind(&RequireCallback, &required_id_, &required_set_));
-    layer_->SetSurfaceId(
-        SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, kArbitraryToken)), 1.f,
-        gfx::Size(1, 1));
+    layer_->SetSurfaceId(SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, 0)),
+                         1.f, gfx::Size(1, 1));
 
     // Layer hasn't been added to tree so no SurfaceSequence generated yet.
     EXPECT_EQ(0u, required_set_.size());
@@ -156,8 +151,8 @@
 
     // Should have SurfaceSequence from first tree.
     SurfaceSequence expected(kArbitraryFrameSinkId, 1u);
-    EXPECT_TRUE(required_id_ == SurfaceId(kArbitraryFrameSinkId,
-                                          LocalFrameId(1, kArbitraryToken)));
+    EXPECT_TRUE(required_id_ ==
+                SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, 0)));
     EXPECT_EQ(1u, required_set_.size());
     EXPECT_TRUE(required_set_.count(expected));
 
@@ -188,8 +183,6 @@
 
   SurfaceId required_id_;
   std::set<SurfaceSequence> required_set_;
-  const base::UnguessableToken kArbitraryToken =
-      base::UnguessableToken::Create();
 };
 
 // Check that SurfaceSequence is sent through swap promise.
@@ -226,8 +219,8 @@
   }
 
   void AfterTest() override {
-    EXPECT_TRUE(required_id_ == SurfaceId(kArbitraryFrameSinkId,
-                                          LocalFrameId(1, kArbitraryToken)));
+    EXPECT_TRUE(required_id_ ==
+                SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, 0)));
     EXPECT_EQ(1u, required_set_.size());
     // Sequence should have been satisfied through Swap, not with the
     // callback.
@@ -266,8 +259,8 @@
   }
 
   void AfterTest() override {
-    EXPECT_TRUE(required_id_ == SurfaceId(kArbitraryFrameSinkId,
-                                          LocalFrameId(1, kArbitraryToken)));
+    EXPECT_TRUE(required_id_ ==
+                SurfaceId(kArbitraryFrameSinkId, LocalFrameId(1, 0)));
     EXPECT_EQ(1u, required_set_.size());
     // Sequence should have been satisfied with the callback.
     EXPECT_TRUE(satisfied_sequence_ ==