[ios] Update swarming dimensions for Xcode 10

Bug: chromium:888513
Change-Id: I55fb5522cc4beee8e657d63bd2a166bce8b7291e
Reviewed-on: https://webrtc-review.googlesource.com/101944
Commit-Queue: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24844}
diff --git "a/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_\050iOS_9.0\051.json" "b/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_\050iOS_9.0\051.json"
index 3957531..7a56d46 100644
--- "a/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_\050iOS_9.0\051.json"
+++ "b/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_\050iOS_9.0\051.json"
@@ -20,14 +20,9 @@
       "device type": "iPhone 5",
       "os": "9.3",
       "dimensions": [
-        {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
-          "pool": "Chrome"
-        }
+        { "os": "Mac-10.13.4", "pool": "Chrome" },
+        { "os": "Mac-10.13.5", "pool": "Chrome" },
+        { "os": "Mac-10.13.6", "pool": "Chrome" }
       ]
     }
   ]
diff --git "a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_11.0\051.json" "b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_11.0\051.json"
index 18e1683..3dad91b 100644
--- "a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_11.0\051.json"
+++ "b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_11.0\051.json"
@@ -20,14 +20,9 @@
       "device type": "iPhone 7",
       "os": "11.0",
       "dimensions": [
-        {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
-          "pool": "Chrome"
-        }
+        { "os": "Mac-10.13.4", "pool": "Chrome" },
+        { "os": "Mac-10.13.5", "pool": "Chrome" },
+        { "os": "Mac-10.13.6", "pool": "Chrome" }
       ]
     }
   ]
diff --git "a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_9.0\051.json" "b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_9.0\051.json"
index 7c957b1..d27cdaa 100644
--- "a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_9.0\051.json"
+++ "b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_\050iOS_9.0\051.json"
@@ -20,14 +20,9 @@
       "device type": "iPhone 6s",
       "os": "9.3",
       "dimensions": [
-        {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
-          "pool": "Chrome"
-        }
+        { "os": "Mac-10.13.4", "pool": "Chrome" },
+        { "os": "Mac-10.13.5", "pool": "Chrome" },
+        { "os": "Mac-10.13.6", "pool": "Chrome" }
       ]
     }
   ]