WebRTC: Update Macs to 10.10 (with Xcode 7)

masters/master.client.webrtc/slaves.cfg

Index: masters/master.client.webrtc/slaves.cfg
diff --git a/masters/master.client.webrtc/slaves.cfg b/masters/master.client.webrtc/slaves.cfg
index 4810ec5aa9b40c085f1d45f0db16fc1536018f82..258115a0df3648f7ecbf13e0669d4b4c48296abb 100644
--- a/masters/master.client.webrtc/slaves.cfg
+++ b/masters/master.client.webrtc/slaves.cfg
@@ -121,7 +121,7 @@ slaves = [
   {
     'master': 'WebRTC',
     'os': 'mac',
-    'version': '10.8',
+    'version': '10.10',
     'bits': '64',
     'builder': [
       'iOS32 Debug',
@@ -139,13 +139,13 @@ slaves = [
       'Mac Asan',
     ],
     'hostname': 'vm%d-m3' % i,
-  } for i in range(672, 674) + [612, 677]
+  } for i in range(672, 675) + [612, 677]

[phoglund_chromium, 2015/11/16 09:36:54]

Where did you move 675 from? Is that the one you mention in the CL description?
If so, where is it removed from its old place?

[kjellander_chromium, 2015/11/16 09:45:12]

This change only adds 674 (from masters/master.client.webrtc.fyi/slaves.cfg). 
Remember that range(x,y) doesn't include y (just y-1)

[phoglund_chromium, 2015/11/16 10:16:42]

Ok, just checking.

 ] + [
   # Mac, bare-metal.
   {
     'master': 'WebRTC',
     'os': 'mac',
-    'version': '10.8',
+    'version': '10.10',
     'bits': '64',
     'builder': [
       'Mac32 Release [large tests]',