Update gn files to support Mozilla build

Bug: webrtc:8670
No-Presubmit: true
Change-Id: I085dc63daa8274b5068540cbf56b6330f40643fa
Reviewed-on: https://webrtc-review.googlesource.com/38920
Commit-Queue: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21624}
diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 479f67f..74bb964 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -55,7 +55,7 @@
   }
 }
 
-if (!rtc_build_ssl) {
+if (!rtc_build_ssl && !build_with_mozilla) {
   config("external_ssl_library") {
     assert(rtc_ssl_root != "",
            "You must specify rtc_ssl_root when rtc_build_ssl==0.")
@@ -511,9 +511,10 @@
 
 rtc_static_library("rtc_base") {
   visibility = [ "*" ]
-  public_deps = [
-    ":rtc_base_generic",
-  ]
+  public_deps = []
+  if (!build_with_mozilla) {
+    public_deps += [ ":rtc_base_generic" ]
+  }
   if (is_win) {
     sources = [
       "noop.cc",
@@ -702,7 +703,7 @@
 
   if (rtc_build_ssl) {
     deps += [ "//third_party/boringssl" ]
-  } else {
+  } else if (!build_with_mozilla) {
     configs += [ ":external_ssl_library" ]
   }