Add multi-architecture support in telemetry.

tools/telemetry/telemetry/core/platform/mac_platform_backend.py

Index: tools/telemetry/telemetry/core/platform/mac_platform_backend.py
diff --git a/tools/telemetry/telemetry/core/platform/mac_platform_backend.py b/tools/telemetry/telemetry/core/platform/mac_platform_backend.py
index afe7f8139d7efdf35aee3956388ec6a8f34e5269..002d5212de3cafccac3b027770cc8a9b2d1d2922 100644
--- a/tools/telemetry/telemetry/core/platform/mac_platform_backend.py
+++ b/tools/telemetry/telemetry/core/platform/mac_platform_backend.py
@@ -4,6 +4,7 @@
 
 import ctypes
 import os
+import platform
 import time
 
 from telemetry import decorators
@@ -126,6 +127,10 @@ class MacPlatformBackend(posix_platform_backend.PosixPlatformBackend):
               'WorkingSetSize': 1024 * int(rss)}
     return {}
 
+  @decorators.Cache
+  def GetArchName(self):
+    return platform.machine()
+
   def GetOSName(self):
     return 'mac'