Android APK tests built from a normal WebRTC checkout.

Restructure how the Android APK tests are compiled now
that we have a Chromium checkout available (since r6938).

This removes the need of several hacks that were needed when
building these targets from inside a Chromium checkout.
By creating a symlink to Chromium's base we can compile the required
targets. This also removes the need of the previously precompiled
binaries we keep in /deps/tools/android at Google code.

All the user needs to do is to add the target_os = ["android"]
entry to his .gclient as described at
https://code.google.com/p/chromium/wiki/AndroidBuildInstructions

Before committing this CL, the Android APK buildbots will need
to be updated.
This also solves http://crbug.com/402594 since the apply_svn_patch.py
usage will be similar to the other standalone bots.
It also solves http://crbug.com/399297

BUG=chromium:399297, chromium:402594
TESTED=Locally compiled all APK targets by running:
GYP_DEFINES="OS=android include_tests=1 enable_tracing=1" gclient runhooks
ninja -C out/Release

checkdeps

R=henrike@webrtc.org, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/22149004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7014 4adac7df-926f-26a2-2b94-8c16560cd09d

setup_links.py

@@ -37,8 +37,6 @@ DIRECTORIES = [
   'google_apis',  # Needed by build/common.gypi.
   'net',
   'testing',
-  'third_party/android_testrunner',
-  'third_party/android_tools',
   'third_party/binutils',
   'third_party/boringssl',
   'third_party/colorama',
@@ -62,6 +60,7 @@ DIRECTORIES = [
   'third_party/syzygy',
   'third_party/usrsctp',
   'third_party/yasm',
+  'third_party/zlib',
   'tools/clang',
   'tools/generate_library_loader',
   'tools/gn',
@@ -74,6 +73,15 @@ DIRECTORIES = [
   'tools/win',
 ]
 
+from sync_chromium import get_target_os_list
+if 'android' in get_target_os_list():
+  DIRECTORIES += [
+    'base',
+    'third_party/android_testrunner',
+    'third_party/android_tools',
+    'tools/android',
+  ]
+
 FILES = {
   '.gn': None,
   'tools/find_depot_tools.py': None,