GN: Fix errors when some variables are set to non-default values.

webrtc/base/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/crypto.gni")
 import("//build/config/ui.gni")
@@ skipping 63 matching lines @@
 if (is_linux && !build_with_chromium) {
   # Provides the same functionality as the //crypto:platform target, which
   # WebRTC cannot use as we don't sync src/crypto from Chromium.
   group("linux_system_ssl") {
     deps = [
       "//third_party/boringssl",
     ]
   }
 }
 
-if (rtc_build_ssl == 0) {
+if (!rtc_build_ssl) {
   config("external_ssl_library") {
     assert(rtc_ssl_root != "",
            "You must specify rtc_ssl_root when rtc_build_ssl==0.")
     include_dirs = [ rtc_ssl_root ]
   }
 }
 
 # The subset of rtc_base approved for use outside of libjingle.
 static_library("rtc_base_approved") {
   defines = []
@@ skipping 404 matching lines @@
         "win32regkey.h",
         "win32socketinit.cc",
         "win32socketinit.h",
         "win32socketserver.cc",
         "win32socketserver.h",
       ]
     }
     if (rtc_build_json) {
       deps += [ "//third_party/jsoncpp" ]
     } else {
-      include_dirs += [ rtc_jsoncpp_root ]
+      include_dirs = [ "$rtc_jsoncpp_root" ]
 
       # When defined changes the include path for json.h to where it is
       # expected to be when building json outside of the standalone build.
       defines += [ "WEBRTC_EXTERNAL_JSON" ]
     }
   }  # !build_with_chromium
 
   # TODO(henrike): issue 3307, make rtc_base build with the Chromium default
   # compiler settings.
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
   if (!is_win) {
     cflags += [ "-Wno-uninitialized" ]
   }
 
   if (rtc_build_ssl) {
     deps += [ "//third_party/boringssl" ]
   } else {
-    configs += [ "external_ssl_library" ]
+    configs += [ ":external_ssl_library" ]
   }
 
   if (is_android) {
     sources += [
       "ifaddrs-android.cc",
       "ifaddrs-android.h",
     ]
 
     libs += [
       "log",
@@ skipping 165 matching lines @@
       "java/src/org/webrtc/Logging.java",
       "java/src/org/webrtc/Size.java",
       "java/src/org/webrtc/ThreadUtils.java",
     ]
 
     deps = [
       "//base:base_java",
     ]
   }
 }