Revert of Convert chart-json to Histograms.

tracing/tracing/results_renderer_unittest.py

Index: tracing/tracing/results_renderer_unittest.py
diff --git a/tracing/tracing/results_renderer_unittest.py b/tracing/tracing/results_renderer_unittest.py
index 6d75c7dba497d7f6283b3799f229c5eb91ee77b4..c1d85350e014c4c9f0d99a5eb9ada3d916f20df9 100644
--- a/tracing/tracing/results_renderer_unittest.py
+++ b/tracing/tracing/results_renderer_unittest.py
@@ -40,14 +40,12 @@
     value0_json = json.dumps(value0, separators=(',', ':'))
 
     results_renderer.RenderHTMLView([], self.output_stream, False)
-    self.output_stream.seek(0)
-    self.assertEquals([], results_renderer.ReadExistingResults(
-        self.output_stream.read()))
+    self.assertEquals([],
+                      results_renderer.ReadExistingResults(self.output_stream))
     results_renderer.RenderHTMLView([value0], self.output_stream, False)
-    self.output_stream.seek(0)
     self.assertEquals(
         sorted([value0]),
-        sorted(results_renderer.ReadExistingResults(self.output_stream.read())))
+        sorted(results_renderer.ReadExistingResults(self.output_stream)))
     self.assertIn(value0_json, self.GetOutputFileContent())
 
   def testExistingResults(self):
@@ -59,10 +57,9 @@
 
     results_renderer.RenderHTMLView([value0], self.output_stream, False)
     results_renderer.RenderHTMLView([value1], self.output_stream, False)
-    self.output_stream.seek(0)
     self.assertEquals(
         sorted([value0, value1]),
-        sorted(results_renderer.ReadExistingResults(self.output_stream.read())))
+        sorted(results_renderer.ReadExistingResults(self.output_stream)))
     self.assertIn(value0_json, self.GetOutputFileContent())
     self.assertIn(value1_json, self.GetOutputFileContent())
 
@@ -75,9 +72,8 @@
 
     results_renderer.RenderHTMLView([value0], self.output_stream, False)
     results_renderer.RenderHTMLView([value1], self.output_stream, True)
-    self.output_stream.seek(0)
     self.assertEquals(
         sorted([value1]),
-        sorted(results_renderer.ReadExistingResults(self.output_stream.read())))
+        sorted(results_renderer.ReadExistingResults(self.output_stream)))
     self.assertNotIn(value0_json, self.GetOutputFileContent())
     self.assertIn(value1_json, self.GetOutputFileContent())