Add cpu_stats for the browser

tools/telemetry/telemetry/core/browser.py

Index: tools/telemetry/telemetry/core/browser.py
diff --git a/tools/telemetry/telemetry/core/browser.py b/tools/telemetry/telemetry/core/browser.py
index a2a9fd5c274f08f21ca1f3772b780fc60f702eb0..51c5d8670986b9bcca5be98e45632bd59060e6ab 100644
--- a/tools/telemetry/telemetry/core/browser.py
+++ b/tools/telemetry/telemetry/core/browser.py
@@ -168,6 +168,27 @@ class Browser(object):
     return result
 
   @property
+  def cpu_stats(self):
+    """Returns a dict of cpu statistics for the system.
+    { 'Browser': {
+        'CpuPercent': S,
+        'CpuProcessTime': T,
+        'TotalTime': U
+      },
+      'Gpu': {},
+      'Renderer': {
+        'CpuPercent': S,
+        'CpuProcessTime': T,
+        'TotalTime': U
+      },
+      'ProcessCount': V,
+    }
+    Any of the above keys may be missing on a per-platform basis.
+    """
+    result = self._GetStatsCommon(self._platform_backend.GetCpuStats)
+    return result
+
+  @property
   def io_stats(self):
     """Returns a dict of IO statistics for the browser:
     { 'Browser': {