[Telemetry] Add file handle & trace value.

tools/telemetry/telemetry/results/page_test_results.py

Index: tools/telemetry/telemetry/results/page_test_results.py
diff --git a/tools/telemetry/telemetry/results/page_test_results.py b/tools/telemetry/telemetry/results/page_test_results.py
index 676e003414de3f2f5ddecf2d26540316287d4189..5ff3ae298da8446e6557bd461ebbeec2c0f99700 100644
--- a/tools/telemetry/telemetry/results/page_test_results.py
+++ b/tools/telemetry/telemetry/results/page_test_results.py
@@ -4,6 +4,7 @@
 
 import collections
 import copy
+import itertools
 import traceback
 
 from telemetry import value as value_module
@@ -62,6 +63,13 @@ class PageTestResults(object):
     return values
 
   @property
+  def all_file_handles(self):
+    all_values = itertools.chain(
+        self.all_summary_values, self.all_page_specific_values)
+    return [fh for fh in map(lambda v: v.GetAssociatedFileHandle(), all_values)
+            if fh is not None]
+
+  @property
   def all_summary_values(self):
     return self._all_summary_values