shill: crypto: use libchromeos's base64 decoder

Some platforms don't have glib enabled. In order to build shill
on such platforms, the crypto code needs to use something
else for base64 decoding.

Fix this, by moving the crypto code to the base64 decoder
in libchromeos.

BUG=b:23003248
TEST=unit tests

Change-Id: I5bb833dd27faba97d9c755684bc400dd7987133b
Reviewed-on: https://chromium-review.googlesource.com/293880
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: mukesh agrawal <quiche@chromium.org>
Trybot-Ready: mukesh agrawal <quiche@chromium.org>
Tested-by: mukesh agrawal <quiche@chromium.org>
diff --git a/crypto_des_cbc_unittest.cc b/crypto_des_cbc_unittest.cc
index c65a288..a606e78 100644
--- a/crypto_des_cbc_unittest.cc
+++ b/crypto_des_cbc_unittest.cc
@@ -10,8 +10,6 @@
 #include <base/files/scoped_temp_dir.h>
 #include <gtest/gtest.h>
 
-#include "shill/glib.h"
-
 using base::FilePath;
 using std::string;
 using std::vector;
@@ -33,10 +31,9 @@
 
 class CryptoDESCBCTest : public Test {
  public:
-  CryptoDESCBCTest() : crypto_(&glib_) {}
+  CryptoDESCBCTest() {}
 
  protected:
-  GLib glib_;  // Use actual GLib for the test.
   CryptoDESCBC crypto_;
 };