Fix x509_certificate_model_openssl.cc to use BoringSSL.

This file in chrome/content didn't have a dependancy on OpenSSL or BoringSSL,
which caused it to get the system OpenSSL headers. This bug teamed up with the
fact that there was a "-lcrypto" left over in the WebRTC gyp file[1] and it
ended up with the system OpenSSL PKCS#7 functions too.

This worked only because of luck before and
X509CertificateModelTest.GetCMSString's luck ran out recently.

This change adds the needed dependancy and updates the code to compile against
BoringSSL.

[1] https://webrtc-codereview.appspot.com/18069004

BUG=none

Review URL: https://codereview.chromium.org/443253003

Cr-Commit-Position: refs/heads/master@{#288879}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288879 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/chrome_common.gypi b/chrome/chrome_common.gypi
index 676fa13..f23a6af 100644
--- a/chrome/chrome_common.gypi
+++ b/chrome/chrome_common.gypi
@@ -665,6 +665,9 @@
             'sources!': [
               'common/net/x509_certificate_model_nss.cc',
             ],
+            'dependencies': [
+              '<(DEPTH)/third_party/boringssl/boringssl.gyp:boringssl',
+            ],
           },
           {  # else !use_openssl: remove the unneeded files
             'sources!': [