Replace libjingle_root with talk_root variable.

This CL is similar to https://review.webrtc.org/9019004/
It is needed in order to be able to build with different
copies of libjingle. Having the libjingle_root variable didn't
make this possible, since relative paths in the .isolate files
ended up at the wrong directory level and .isolate files doesn't
support all the normal GYP variables like <(DEPTH).

BUG=chromium:343106
TEST=trybots passing compile step with clobber.
R=tommi@webrtc.org, wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/15709004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6380 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/all.gyp b/all.gyp
index bd8ee13..a399a78 100644
--- a/all.gyp
+++ b/all.gyp
@@ -8,7 +8,7 @@
 
 {
   'variables': {
-    'libjingle_root%': '<(DEPTH)',
+    'talk_root%': '<(DEPTH)/talk',
   },
   'targets': [
     {
@@ -17,9 +17,9 @@
       'dependencies': [
         'third_party/openmax_dl/dl/dl.gyp:*',
         'webrtc/webrtc.gyp:*',
-        '<(libjingle_root)/talk/libjingle.gyp:*',
-        '<(libjingle_root)/talk/libjingle_examples.gyp:*',
-        '<(libjingle_root)/talk/libjingle_tests.gyp:*',
+        '<(talk_root)/libjingle.gyp:*',
+        '<(talk_root)/libjingle_examples.gyp:*',
+        '<(talk_root)/libjingle_tests.gyp:*',
       ],
       'conditions': [
         ['OS=="android"', {
diff --git a/talk/build/common.gypi b/talk/build/common.gypi
index 8261c20..85d2f58 100644
--- a/talk/build/common.gypi
+++ b/talk/build/common.gypi
@@ -30,8 +30,8 @@
 {
   'variables': {
     'webrtc_root%': '<(DEPTH)/webrtc',
-    # TODO(ronghuawu): Chromium build will need a different libjingle_root.
-    'libjingle_root%': '<(DEPTH)',
+    # TODO(ronghuawu): Chromium build will need a different talk_root.
+    'talk_root%': '<(DEPTH)/talk',
     # TODO(ronghuawu): For now, disable the Chrome plugins, which causes a
     # flood of chromium-style warnings.
     'clang_use_chrome_plugins%': 0,
@@ -46,7 +46,7 @@
   },
   'target_defaults': {
     'include_dirs': [
-      '<(libjingle_root)',
+      '<(talk_root)/..',
       '<(DEPTH)',
       '../../third_party',
       '../../third_party/webrtc',