cc: Remove unused_memory_limit_in_bytes field from GlobalStateThatImpactsTilePriority.

cc/resources/tile_priority.cc

Index: cc/resources/tile_priority.cc
diff --git a/cc/resources/tile_priority.cc b/cc/resources/tile_priority.cc
index 9e81d6c17f67e02dfabbdf09cd7da9cced2c3373..3bf29680766bd782d3ac414a3b47f55d60851c96 100644
--- a/cc/resources/tile_priority.cc
+++ b/cc/resources/tile_priority.cc
@@ -106,8 +106,6 @@ scoped_ptr<base::Value> GlobalStateThatImpactsTilePriority::AsValue() const {
              TileMemoryLimitPolicyAsValue(memory_limit_policy).release());
   state->SetInteger("soft_memory_limit_in_bytes", soft_memory_limit_in_bytes);
   state->SetInteger("hard_memory_limit_in_bytes", hard_memory_limit_in_bytes);
-  state->SetInteger("unused_memory_limit_in_bytes",
-                    unused_memory_limit_in_bytes);
   state->SetInteger("num_resources_limit", num_resources_limit);
   state->Set("tree_priority", TreePriorityAsValue(tree_priority).release());
   return state.PassAs<base::Value>();