Remove references to build_with_libjingle and libjingle_java GYP variables.

talk/app/webrtc/objc/README

 This directory contains the ObjectiveC implementation of the
 webrtc::PeerConnection API.  This can be built for Mac or iOS.  This
 file describes building the API, unit test, and AppRTCDemo sample app.
 
 Prerequisites:
 - Make sure gclient is checking out tools necessary to target iOS: your
   .gclient file should contain a line like:
   target_os = ['ios', 'mac']
   Make sure to re-run gclient sync after adding this to download the tools.
 
 - Set up webrtc-related $GYP_DEFINES; example shell functions that set
   up for building for iOS-device, iOS-simulator, and Mac (resp) are:
 function wrbase() {
-  cd /path/to/webrtc/trunk
-  export GYP_DEFINES="build_with_libjingle=1 build_with_chromium=0"
-  export GYP_GENERATORS="ninja"
+  cd /path/to/webrtc/src
 }
 
 function wrios() {
   wrbase
   export GYP_DEFINES="$GYP_DEFINES OS=ios"
   export GYP_GENERATOR_FLAGS="$GYP_GENERATOR_FLAGS output_dir=out_ios"
   export GYP_CROSSCOMPILE=1
 }
 
 function wrios32() {
@@ skipping 34 matching lines @@
 
 - To build & launch the sample app on the iOS simulator:
   wrsim && ./webrtc/build/gyp_webrtc && ninja -C out_sim/Debug iossim AppRTCDemo && \
       ./out_sim/Debug/iossim out_sim/Debug/AppRTCDemo.app
 
 - To build & sign the sample app for an iOS device (32 bit):
   wrios32 && ./webrtc/build/gyp_webrtc && ninja -C out_ios/Debug-iphoneos AppRTCDemo
 
 - To build & sign the sample app for an iOS device (64 bit):
   wrios64 && ./webrtc/build/gyp_webrtc && ninja -C out_ios/Debug-iphoneos AppRTCDemo