Move histogram_manager from components/metrics to components/cronet

components/cronet/histogram_manager_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/metrics/histogram_manager.h"
+#include "components/cronet/histogram_manager.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace metrics {
 
-// TODO(mef): crbug.com/441441. Move components/metrics/histogram_manager.*
-// files into components/android/cronet.
 // TODO(rtenneti): enable flaky HistogramBucketFields unit test.
 TEST(HistogramManager, DISABLED_HistogramBucketFields) {

[Alexei Svitkine (slow), 2015/04/08 17:56:37]

Any idea why this is still disabled/flaky? Are you planning to take a look at
that after this?

Otherwise, this test wouldn't actually be running.

[mef, 2015/04/08 18:06:04]

Good question, I probably should, although I'm not sure how to test this. 
I could drop this unittest and test through java instrumentation, but I suppose
that we may want to use HistogramManager in Cronet on iOS in foreseeable future.
Raman, do you remember, what was causing test flakiness?

[ramant (doing other things), 2015/04/08 18:22:13]

I don't remember. Is it possible try LOCAL_HISTOGRAM_ENUMERATION and see if it
works or not. The difference between this UMA_... whether the histogram is used
for upload or not.

   // Capture histograms at the start of the test to avoid later GetDeltas()
   // calls picking them up.
   std::vector<uint8> data_init;
   HistogramManager::GetInstance()->GetDeltas(&data_init);
 
   // kNoFlags filter should record all histograms.
   UMA_HISTOGRAM_ENUMERATION("UmaHistogramManager", 1, 2);

[mef, 2015/04/08 18:06:04]

I've got presubmit warning that "UmaHistogramManager" is not found in
histograms.xml. Is there a better name for testing?

[Alexei Svitkine (slow), 2015/04/08 18:11:38]

Hmm, the presubmit should probably be ignoring _unittest.cc files.

You can probably just fix that pretty easily here:

https://code.google.com/p/chromium/codesearch#chromium/src/PRESUBMIT.py

[Alexei Svitkine (slow), 2015/04/08 18:12:07]

Correct link:
https://code.google.com/p/chromium/codesearch#chromium/src/PRESUBMIT.py&l=387

 
   std::vector<uint8> data;
   EXPECT_TRUE(HistogramManager::GetInstance()->GetDeltas(&data));
   EXPECT_FALSE(data.empty());
   ChromeUserMetricsExtension uma_proto;
   EXPECT_TRUE(uma_proto.ParseFromArray(
       reinterpret_cast<const char*>(&data[0]), data.size()));
   EXPECT_FALSE(data.empty());
 
   const HistogramEventProto& histogram_proto =
@@ skipping 14 matching lines @@
 
   const HistogramEventProto& histogram_proto2 =
       uma_proto2.histogram_event(uma_proto2.histogram_event_size() - 1);
   ASSERT_EQ(1, histogram_proto2.bucket_size());
   EXPECT_LE(0, histogram_proto2.bucket(0).min());
   EXPECT_LE(3, histogram_proto2.bucket(0).max());
   EXPECT_EQ(1, histogram_proto2.bucket(0).count());
 }
 
 }  // namespace metrics