Add performance_browser_tests to some Mac bots

testing/buildbot/chromium.perf.json

Index: testing/buildbot/chromium.perf.json
diff --git a/testing/buildbot/chromium.perf.json b/testing/buildbot/chromium.perf.json
index d573d97ffe6b751daf8fdfa4859d1c2b9316a057..adc8a79fa4addd0722e011045837604749f52f7b 100644
--- a/testing/buildbot/chromium.perf.json
+++ b/testing/buildbot/chromium.perf.json
@@ -28406,6 +28406,26 @@
         }
       },
       {
+        "args": [],
+        "isolate_name": "performance_browser_tests",
+        "name": "performance_browser_tests",
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "gpu": "8086:1626",
+              "id": "build124-b1",
+              "os": "Mac-10.11",
+              "pool": "Chrome-perf"
+            }
+          ],
+          "expiration": 36000,
+          "hard_timeout": 7200,
+          "ignore_task_failure": false,
+          "io_timeout": 3600
+        }
+      },
+      {
         "args": [
           "power.idle_platform",
           "-v",
@@ -41216,6 +41236,26 @@
         }
       },
       {
+        "args": [],
+        "isolate_name": "performance_browser_tests",
+        "name": "performance_browser_tests",
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "gpu": "1002:6821",
+              "id": "build128-b1",
+              "os": "Mac-10.11",
+              "pool": "Chrome-perf"
+            }
+          ],
+          "expiration": 36000,
+          "hard_timeout": 7200,
+          "ignore_task_failure": false,
+          "io_timeout": 3600
+        }
+      },
+      {
         "args": [
           "power.idle_platform",
           "-v",
@@ -47621,6 +47661,26 @@
         }
       },
       {
+        "args": [],
+        "isolate_name": "performance_browser_tests",
+        "name": "performance_browser_tests",
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "gpu": "8086:0d26",
+              "id": "build6-b1",
+              "os": "Mac-10.11",
+              "pool": "Chrome-perf"
+            }
+          ],
+          "expiration": 36000,
+          "hard_timeout": 7200,
+          "ignore_task_failure": false,
+          "io_timeout": 3600
+        }
+      },
+      {
         "args": [
           "power.idle_platform",
           "-v",