update_engine: remove redundant utils functions

utils::MapContainsKey and utils::SetContainsKey are the same
function and could be unified with more general templating, but
that would just be a reimplementation of base::ContainsKey so we
can just use that instead. Additionally, base::ContainsValue can
be used in place of utils::VectorContainsValue.

BUG=None
TEST=unit tests

Change-Id: Ia8fee68ca8d6a87d232f89380c1e4144b598fad9
Reviewed-on: https://chromium-review.googlesource.com/882455
Commit-Ready: Eric Caruso <ejcaruso@chromium.org>
Tested-by: Eric Caruso <ejcaruso@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Alex Deymo <deymo@google.com>

payload_generator/tarjan.cc

diff --git a/payload_generator/tarjan.cc b/payload_generator/tarjan.cc
index 98e29f9..d99ae12 100644
--- a/payload_generator/tarjan.cc
+++ b/payload_generator/tarjan.cc
@@ -19,8 +19,7 @@
 #include <vector>
 
 #include <base/logging.h>
-
-#include "update_engine/common/utils.h"
+#include <base/stl_util.h>
 
 using std::min;
 using std::vector;
@@ -59,7 +58,7 @@
       Tarjan(vertex_next, graph);
       (*graph)[vertex].lowlink = min((*graph)[vertex].lowlink,
                                      (*graph)[vertex_next].lowlink);
-    } else if (utils::VectorContainsValue(stack_, vertex_next)) {
+    } else if (base::ContainsValue(stack_, vertex_next)) {
       (*graph)[vertex].lowlink = min((*graph)[vertex].lowlink,
                                      (*graph)[vertex_next].index);
     }
@@ -73,7 +72,7 @@
       component.push_back(other_vertex);
     } while (other_vertex != vertex && !stack_.empty());
 
-    if (utils::VectorContainsValue(component, required_vertex_)) {
+    if (base::ContainsValue(component, required_vertex_)) {
       components_.resize(components_.size() + 1);
       component.swap(components_.back());
     }