Move memory histograms generation to MetricsMemoryDetails.

chrome/browser/memory_details_browsertest.cc

-// Copyright 2015 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 "chrome/browser/memory_details.h"
-
-#include "base/message_loop/message_loop.h"
-#include "base/test/histogram_tester.h"
-#include "chrome/test/base/in_process_browser_test.h"
-#include "content/public/test/test_utils.h"
-
-namespace {
-
-class TestMemoryDetails : public MemoryDetails {
- public:
-  TestMemoryDetails() {}
-
-  void StartFetchAndWait() {
-    StartFetch(UPDATE_USER_METRICS);
-    content::RunMessageLoop();
-  }
-
- private:
-  ~TestMemoryDetails() override {}
-
-  void OnDetailsAvailable() override {
-    // Exit the loop initiated by StartFetchAndWait().
-    base::MessageLoop::current()->Quit();
-  }
-
-  DISALLOW_COPY_AND_ASSIGN(TestMemoryDetails);
-};
-
-}  // namespace
-
-class MemoryDetailsBrowserTest : public InProcessBrowserTest {
- public:
-  MemoryDetailsBrowserTest() {}
-  ~MemoryDetailsBrowserTest() override {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(MemoryDetailsBrowserTest);
-};
-
-IN_PROC_BROWSER_TEST_F(MemoryDetailsBrowserTest, TestMemoryDetails) {
-  base::HistogramTester histogram_tester;
-
-  scoped_refptr<TestMemoryDetails> details(new TestMemoryDetails);
-  details->StartFetchAndWait();
-
-  // Memory.Browser histogram should have a single non-0 sample recorded.
-  histogram_tester.ExpectTotalCount("Memory.Browser", 1);
-  scoped_ptr<base::HistogramSamples> samples(
-      histogram_tester.GetHistogramSamplesSinceCreation("Memory.Browser"));
-  ASSERT_TRUE(samples);
-  EXPECT_NE(0, samples->sum());
-}