WebRTC: Update to new machines after a->b lab move.

masters/master.chromium.webrtc.fyi/slaves.cfg

Index: masters/master.chromium.webrtc.fyi/slaves.cfg
diff --git a/masters/master.chromium.webrtc.fyi/slaves.cfg b/masters/master.chromium.webrtc.fyi/slaves.cfg
index f0750ba5740b4e5058c96c71bc43d1f991997c61..e83cdf7059b40a117110b44de5878f050d374804 100644
--- a/masters/master.chromium.webrtc.fyi/slaves.cfg
+++ b/masters/master.chromium.webrtc.fyi/slaves.cfg
@@ -43,7 +43,7 @@ slaves = [
     'version': 'precise',
     'bits': '64',
     'builder': ['Android Tests (dbg) (L Nexus5)'],
-    'hostname': 'build28-a1',
+    'hostname': 'build94-b1',
   },
   {
     'master': 'ChromiumWebRTCFYI',
@@ -67,7 +67,7 @@ slaves = [
     'version': 'precise',
     'bits': '64',
     'builder': ['Android Tests (dbg) (L Nexus9)'],
-    'hostname': 'build25-a1',
+    'hostname': 'build93-b1',
   },
   # Mac.
  {
@@ -125,7 +125,7 @@ slaves = [
     'version': 'win7',
     'bits': '64',
     'builder': ['Win7 Tester'],
-    'hostname': 'build83-a1',
+    'hostname': 'build98-b1',
   },
   {
     'master': 'ChromiumWebRTCFYI',
@@ -133,6 +133,6 @@ slaves = [
     'version': 'win10',
     'bits': '64',
     'builder': ['Win10 Tester'],
-    'hostname': 'build3-a1',
+    'hostname': 'build96-b1',
   },
 ]