Revert "Create and pass shared-histogram-allocator from browser to renderer."

chrome/browser/metrics/subprocess_metrics_provider_unittest.cc

-// Copyright 2016 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/metrics/subprocess_metrics_provider.h"
-
-#include <memory>
-
-#include "base/memory/ptr_util.h"
-#include "base/memory/shared_memory.h"
-#include "base/metrics/histogram.h"
-#include "base/metrics/histogram_flattener.h"
-#include "base/metrics/histogram_snapshot_manager.h"
-#include "base/metrics/persistent_histogram_allocator.h"
-#include "base/metrics/persistent_memory_allocator.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace {
-
-const uint32_t TEST_MEMORY_SIZE = 64 << 10;  // 64 KiB
-
-class HistogramFlattenerDeltaRecorder : public base::HistogramFlattener {
- public:
-  HistogramFlattenerDeltaRecorder() {}
-
-  void RecordDelta(const base::HistogramBase& histogram,
-                   const base::HistogramSamples& snapshot) override {
-    recorded_delta_histogram_names_.push_back(histogram.histogram_name());
-  }
-
-  void InconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) override {
-    ASSERT_TRUE(false);
-  }
-
-  void UniqueInconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) override {
-    ASSERT_TRUE(false);
-  }
-
-  void InconsistencyDetectedInLoggedCount(int amount) override {
-    ASSERT_TRUE(false);
-  }
-
-  std::vector<std::string> GetRecordedDeltaHistogramNames() {
-    return recorded_delta_histogram_names_;
-  }
-
- private:
-  std::vector<std::string> recorded_delta_histogram_names_;
-
-  DISALLOW_COPY_AND_ASSIGN(HistogramFlattenerDeltaRecorder);
-};
-
-}  // namespace
-
-class SubprocessMetricsProviderTest : public testing::Test {
- protected:
-  SubprocessMetricsProviderTest() {
-    // Get this first so it isn't created inside a persistent allocator.
-    base::PersistentHistogramAllocator::GetCreateHistogramResultHistogram();
-
-    // RecordHistogramSnapshots needs to be called beause it uses a histogram
-    // macro which caches a pointer to a histogram. If not done before setting
-    // a persistent global allocator, then it would point into memory that
-    // will go away. The easiest way to call it is through an existing utility
-    // method.
-    GetSnapshotHistogramCount();
-
-    // Create some shared-memory to pass between global allocator and provider.
-    std::unique_ptr<base::SharedMemory> shmem(new base::SharedMemory());
-    DCHECK(shmem->CreateAndMapAnonymous(TEST_MEMORY_SIZE));
-
-    // Keep a weak-pointer to the shared memory since it will be hidden once
-    // made part of the global histogram allocator.
-    shared_memory_ = shmem.get();
-
-    // Use the shared memory for all histograms created by this process.
-    base::GlobalHistogramAllocator::CreateWithSharedMemory(
-        std::move(shmem), TEST_MEMORY_SIZE, 0, "");
-
-    // Enable metrics reporting by default.
-    provider_.OnRecordingEnabled();
-  }
-
-  ~SubprocessMetricsProviderTest() override {
-    base::GlobalHistogramAllocator::ReleaseForTesting();
-  }
-
-  SubprocessMetricsProvider* provider() { return &provider_; }
-
-  base::SharedMemory* shared_memory() { return shared_memory_; }
-
-  std::unique_ptr<base::PersistentHistogramAllocator> GetDuplicateAllocator() {
-    base::SharedMemoryHandle memory_handle;
-    DCHECK(shared_memory_->ShareToProcess(base::GetCurrentProcessHandle(),
-                                          &memory_handle));
-
-    std::unique_ptr<base::SharedMemory> shmem(
-        new base::SharedMemory(memory_handle, /*readonly=*/false));
-    DCHECK(shmem->Map(TEST_MEMORY_SIZE));
-
-    return WrapUnique(new base::PersistentHistogramAllocator(
-        WrapUnique(new base::SharedPersistentMemoryAllocator(
-            std::move(shmem), 0, "", false))));
-  }
-
-  size_t GetSnapshotHistogramCount() {
-    HistogramFlattenerDeltaRecorder flattener;
-    base::HistogramSnapshotManager snapshot_manager(&flattener);
-    snapshot_manager.StartDeltas();
-    provider_.RecordHistogramSnapshots(&snapshot_manager);
-    snapshot_manager.FinishDeltas();
-    return flattener.GetRecordedDeltaHistogramNames().size();
-  }
-
-  void EnableRecording() { provider_.OnRecordingEnabled(); }
-  void DisableRecording() { provider_.OnRecordingDisabled(); }
-
-  void RegisterSubprocessAllocator(
-      int id,
-      std::unique_ptr<base::PersistentHistogramAllocator> allocator) {
-    provider_.RegisterSubprocessAllocator(id, std::move(allocator));
-  }
-
-  void DeregisterSubprocessAllocator(int id) {
-    provider_.DeregisterSubprocessAllocator(id);
-  }
-
- private:
-  SubprocessMetricsProvider provider_;
-  base::SharedMemory* shared_memory_;
-
-  DISALLOW_COPY_AND_ASSIGN(SubprocessMetricsProviderTest);
-};
-
-TEST_F(SubprocessMetricsProviderTest, SnapshotMetrics) {
-  base::HistogramBase* foo = base::Histogram::FactoryGet("foo", 1, 100, 10, 0);
-  base::HistogramBase* bar = base::Histogram::FactoryGet("bar", 1, 100, 10, 0);
-  foo->Add(42);
-  bar->Add(84);
-
-  // Register an allocator that duplicates the global allocator.
-  RegisterSubprocessAllocator(123, GetDuplicateAllocator());
-
-  // Recording should find the two histograms created in persistent memory.
-  EXPECT_EQ(2U, GetSnapshotHistogramCount());
-
-  // A second run should have nothing to produce.
-  EXPECT_EQ(0U, GetSnapshotHistogramCount());
-
-  // Create a new histogram and update existing ones. Should now report 3 items.
-  base::HistogramBase* baz = base::Histogram::FactoryGet("baz", 1, 100, 10, 0);
-  baz->Add(1969);
-  foo->Add(10);
-  bar->Add(20);
-  EXPECT_EQ(3U, GetSnapshotHistogramCount());
-
-  // Ensure that deregistering still keeps allocator around for final report.
-  foo->Add(10);
-  bar->Add(20);
-  DeregisterSubprocessAllocator(123);
-  EXPECT_EQ(2U, GetSnapshotHistogramCount());
-
-  // Further snapshots should be empty even if things have changed.
-  foo->Add(10);
-  bar->Add(20);
-  EXPECT_EQ(0U, GetSnapshotHistogramCount());
-}
-
-TEST_F(SubprocessMetricsProviderTest, EnableDisable) {
-  base::HistogramBase* foo = base::Histogram::FactoryGet("foo", 1, 100, 10, 0);
-  base::HistogramBase* bar = base::Histogram::FactoryGet("bar", 1, 100, 10, 0);
-
-  // Simulate some "normal" operation...
-  RegisterSubprocessAllocator(123, GetDuplicateAllocator());
-  foo->Add(42);
-  bar->Add(84);
-  EXPECT_EQ(2U, GetSnapshotHistogramCount());
-  foo->Add(42);
-  bar->Add(84);
-  EXPECT_EQ(2U, GetSnapshotHistogramCount());
-
-  // Ensure that disable/enable reporting won't affect "live" allocators.
-  DisableRecording();
-  EnableRecording();
-  foo->Add(42);
-  bar->Add(84);
-  EXPECT_EQ(2U, GetSnapshotHistogramCount());
-
-  // Ensure that allocators are released when reporting is disabled.
-  DisableRecording();
-  DeregisterSubprocessAllocator(123);
-  EnableRecording();
-  foo->Add(42);
-  bar->Add(84);
-  EXPECT_EQ(0U, GetSnapshotHistogramCount());
-
-  // Ensure that allocators added when reporting disabled will work if enabled.
-  DisableRecording();
-  RegisterSubprocessAllocator(123, GetDuplicateAllocator());
-  EnableRecording();
-  foo->Add(42);
-  bar->Add(84);
-  EXPECT_EQ(2U, GetSnapshotHistogramCount());
-
-  // Ensure that last-chance allocators are released if reporting is disabled.
-  DeregisterSubprocessAllocator(123);
-  DisableRecording();
-  EnableRecording();
-  foo->Add(42);
-  bar->Add(84);
-  EXPECT_EQ(0U, GetSnapshotHistogramCount());
-}