Remove the rtc_relative_path GYP variable and similar defines

The defines that can be used to alter the include paths for Expat, SRTP
and gtest are no longer needed in WebRTC or Chromium. Let's remove them
to simplify the GYP a little.

Removed defines:
EXPAT_RELATIVE_PATH
GTEST_RELATIVE_PATH
SRTP_RELATIVE_PATH

They're all set in the Chromium build so this shouldn't affect Chromium:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/libjingle/libjingle.gyp

BUG=webrtc:4256
NOTRY=True
NOPRESUBMIT=True

Review URL: https://codereview.webrtc.org/1903553003

Cr-Commit-Position: refs/heads/master@{#12467}
diff --git a/webrtc/base/base_tests.gyp b/webrtc/base/base_tests.gyp
index 73eeb0d..11aea29 100644
--- a/webrtc/base/base_tests.gyp
+++ b/webrtc/base/base_tests.gyp
@@ -23,19 +23,11 @@
         'testechoserver.h',
         'testutils.h',
       ],
-      'defines': [
-        'GTEST_RELATIVE_PATH',
-      ],
       'dependencies': [
         'base.gyp:rtc_base',
         '<(DEPTH)/testing/gtest.gyp:gtest',
         '<(webrtc_root)/test/test.gyp:field_trial',
       ],
-      'direct_dependent_settings': {
-        'defines': [
-          'GTEST_RELATIVE_PATH',
-        ],
-      },
       'export_dependent_settings': [
         '<(DEPTH)/testing/gtest.gyp:gtest',
       ],
diff --git a/webrtc/base/gunit.h b/webrtc/base/gunit.h
index 1a6c363..986d4dc 100644
--- a/webrtc/base/gunit.h
+++ b/webrtc/base/gunit.h
@@ -13,11 +13,7 @@
 
 #include "webrtc/base/logging.h"
 #include "webrtc/base/thread.h"
-#if defined(GTEST_RELATIVE_PATH)
 #include "testing/gtest/include/gtest/gtest.h"
-#else
-#include "testing/base/public/gunit.h"
-#endif
 
 // Wait until "ex" is true, or "timeout" expires.
 #define WAIT(ex, timeout)                                                     \
diff --git a/webrtc/base/gunit_prod.h b/webrtc/base/gunit_prod.h
index dc39bbd..9850ed8 100644
--- a/webrtc/base/gunit_prod.h
+++ b/webrtc/base/gunit_prod.h
@@ -15,10 +15,7 @@
 // Android doesn't use gtest at all, so anything that relies on gtest should
 // check this define first.
 #define NO_GTEST
-#elif defined (GTEST_RELATIVE_PATH)
-#include "gtest/gtest_prod.h"
-#else
-#include "testing/base/gunit_prod.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
 #endif
 
 #endif  // WEBRTC_BASE_GUNIT_PROD_H_
diff --git a/webrtc/build/common.gypi b/webrtc/build/common.gypi
index f8446d9..948cc8a 100644
--- a/webrtc/build/common.gypi
+++ b/webrtc/build/common.gypi
@@ -64,7 +64,6 @@
     'webrtc_vp9_dir%': '<(webrtc_vp9_dir)',
     'include_ilbc%': '<(include_ilbc)',
     'include_opus%': '<(include_opus)',
-    'rtc_relative_path%': 1,
     'external_libraries%': '0',
     'json_root%': '<(DEPTH)/third_party/jsoncpp/source/include/',
     # openssl needs to be defined or gyp will complain. Is is only used when
@@ -238,9 +237,6 @@
            '<!@(pkg-config --cflags dbus-glib-1)',
          ],
       }],
-      ['rtc_relative_path==1', {
-        'defines': ['EXPAT_RELATIVE_PATH',],
-      }],
       ['os_posix==1', {
         'configurations': {
           'Debug_Base': {
diff --git a/webrtc/libjingle/xmllite/xmlbuilder.h b/webrtc/libjingle/xmllite/xmlbuilder.h
index 354bf0b..ea452db 100644
--- a/webrtc/libjingle/xmllite/xmlbuilder.h
+++ b/webrtc/libjingle/xmllite/xmlbuilder.h
@@ -16,11 +16,7 @@
 #include "webrtc/libjingle/xmllite/xmlparser.h"
 #include "webrtc/base/scoped_ptr.h"
 
-#ifdef EXPAT_RELATIVE_PATH
 #include "expat.h"
-#else
-#include "third_party/expat/v2_0_1/Source/lib/expat.h"
-#endif  // EXPAT_RELATIVE_PATH
 
 namespace buzz {
 
diff --git a/webrtc/libjingle/xmllite/xmlparser.h b/webrtc/libjingle/xmllite/xmlparser.h
index 131c585..00d562e 100644
--- a/webrtc/libjingle/xmllite/xmlparser.h
+++ b/webrtc/libjingle/xmllite/xmlparser.h
@@ -14,11 +14,7 @@
 #include <string>
 
 #include "webrtc/libjingle/xmllite/xmlnsstack.h"
-#ifdef EXPAT_RELATIVE_PATH
 #include "expat.h"
-#else
-#include "third_party/expat/v2_0_1/Source/lib/expat.h"
-#endif  // EXPAT_RELATIVE_PATH
 
 struct XML_ParserStruct;
 typedef struct XML_ParserStruct* XML_Parser;
diff --git a/webrtc/libjingle/xmpp/xmppstanzaparser.cc b/webrtc/libjingle/xmpp/xmppstanzaparser.cc
index 035bb0b..87398bc 100644
--- a/webrtc/libjingle/xmpp/xmppstanzaparser.cc
+++ b/webrtc/libjingle/xmpp/xmppstanzaparser.cc
@@ -13,11 +13,7 @@
 #include "webrtc/libjingle/xmllite/xmlelement.h"
 #include "webrtc/libjingle/xmpp/constants.h"
 #include "webrtc/base/common.h"
-#ifdef EXPAT_RELATIVE_PATH
 #include "expat.h"
-#else
-#include "third_party/expat/v2_0_1/Source/lib/expat.h"
-#endif
 
 namespace buzz {
 
diff --git a/webrtc/pc/externalhmac.cc b/webrtc/pc/externalhmac.cc
index d88cfdc..8eeec11 100644
--- a/webrtc/pc/externalhmac.cc
+++ b/webrtc/pc/externalhmac.cc
@@ -15,13 +15,8 @@
 #include <stdlib.h>  // For malloc/free.
 
 extern "C" {
-#ifdef SRTP_RELATIVE_PATH
-#include "crypto_kernel.h"  // NOLINT
-#include "srtp.h"  // NOLINT
-#else
 #include "third_party/libsrtp/srtp/crypto/include/crypto_kernel.h"
 #include "third_party/libsrtp/srtp/include/srtp.h"
-#endif  // SRTP_RELATIVE_PATH
 }
 
 #include "webrtc/base/logging.h"
diff --git a/webrtc/pc/externalhmac.h b/webrtc/pc/externalhmac.h
index 74652b0..d0e112c 100644
--- a/webrtc/pc/externalhmac.h
+++ b/webrtc/pc/externalhmac.h
@@ -31,11 +31,7 @@
 
 #include "webrtc/base/basictypes.h"
 extern "C" {
-#ifdef SRTP_RELATIVE_PATH
-#include "auth.h"  // NOLINT
-#else
 #include "third_party/libsrtp/srtp/crypto/include/auth.h"
-#endif  // SRTP_RELATIVE_PATH
 }
 
 #define EXTERNAL_HMAC_SHA1 HMAC_SHA1 + 1
diff --git a/webrtc/pc/pc.gyp b/webrtc/pc/pc.gyp
index b07f7b7..afe8cad 100755
--- a/webrtc/pc/pc.gyp
+++ b/webrtc/pc/pc.gyp
@@ -10,7 +10,6 @@
   'includes': ['../build/common.gypi'],
   'variables': {
     'rtc_pc_defines': [
-      'SRTP_RELATIVE_PATH',
       'HAVE_SCTP',
       'HAVE_SRTP',
     ],
diff --git a/webrtc/pc/srtpfilter.cc b/webrtc/pc/srtpfilter.cc
index e8ea289..7257deb 100644
--- a/webrtc/pc/srtpfilter.cc
+++ b/webrtc/pc/srtpfilter.cc
@@ -27,13 +27,8 @@
 
 #ifdef HAVE_SRTP
 extern "C" {
-#ifdef SRTP_RELATIVE_PATH
-#include "srtp.h"  // NOLINT
-#include "srtp_priv.h"  // NOLINT
-#else
 #include "third_party/libsrtp/srtp/include/srtp.h"
 #include "third_party/libsrtp/srtp/include/srtp_priv.h"
-#endif  // SRTP_RELATIVE_PATH
 }
 #ifdef  ENABLE_EXTERNAL_AUTH
 #include "webrtc/pc/externalhmac.h"
diff --git a/webrtc/pc/srtpfilter_unittest.cc b/webrtc/pc/srtpfilter_unittest.cc
index 2eee35c..7990ef1 100644
--- a/webrtc/pc/srtpfilter_unittest.cc
+++ b/webrtc/pc/srtpfilter_unittest.cc
@@ -16,11 +16,7 @@
 #include "webrtc/p2p/base/sessiondescription.h"
 #include "webrtc/pc/srtpfilter.h"
 extern "C" {
-#ifdef SRTP_RELATIVE_PATH
-#include "crypto/include/err.h"
-#else
 #include "third_party/libsrtp/srtp/crypto/include/err.h"
-#endif
 }
 
 using rtc::CS_AES_CM_128_HMAC_SHA1_80;
diff --git a/webrtc/webrtc_tests.gypi b/webrtc/webrtc_tests.gypi
index 229f7b6..b44fa53 100644
--- a/webrtc/webrtc_tests.gypi
+++ b/webrtc/webrtc_tests.gypi
@@ -270,9 +270,6 @@
         'base/socketaddress_unittest.cc',
         'base/virtualsocket_unittest.cc',
       ],
-      'defines': [
-        'GTEST_RELATIVE_PATH',
-      ],
       'dependencies': [
         '<(DEPTH)/testing/gtest.gyp:gtest',
         'base/base.gyp:rtc_base',