Persist setup metrics and have Chrome report them during UMA upload.

chrome/browser/metrics/chrome_setup_metrics_provider_unittest.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/metrics/chrome_setup_metrics_provider.h"
+
+#include "base/basictypes.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_persistence.h"
+#include "base/metrics/persistent_memory_allocator.h"
+#include "base/prefs/pref_registry_simple.h"
+#include "base/prefs/testing_pref_service.h"
+#include "chrome/installer/util/google_update_constants.h"
+#include "components/metrics/metrics_pref_names.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using namespace base;
+
+class ChromeSetupMetricsProviderTest : public testing::Test {
+ protected:
+  ChromeSetupMetricsProviderTest() : prefs_(new TestingPrefServiceSimple) {
+    EXPECT_TRUE(temp_dir_.CreateUniqueTempDir());
+    prefs_->registry()->RegisterInt64Pref(metrics::prefs::kSetupMetricsLastSeen,
+                                          0);
+  }
+
+  TestingPrefServiceSimple* prefs() { return prefs_.get(); }
+  FilePath temp_dir() { return temp_dir_.path(); }
+  FilePath metrics_file() {
+    return temp_dir_.path().AppendASCII(
+        google_update::kSetupHistogramAllocatorName);
+  }
+
+  ChromeSetupMetricsProvider* provider() {
+    if (!provider_) {
+      provider_.reset(new ChromeSetupMetricsProvider(nullptr, prefs()));
+      provider_->SetProgramDirectory(temp_dir());
+    }
+    return provider_.get();
+  }
+
+ private:
+  ScopedTempDir temp_dir_;
+  scoped_ptr<TestingPrefServiceSimple> prefs_;
+  scoped_ptr<ChromeSetupMetricsProvider> provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeSetupMetricsProviderTest);
+};
+
+
+TEST_F(ChromeSetupMetricsProviderTest, AccessMetrics) {
+  ASSERT_FALSE(PathExists(metrics_file()));
+
+  {
+    SetPersistentHistogramMemoryAllocator(
+        new LocalPersistentMemoryAllocator(
+            64 << 10, 0, google_update::kSetupHistogramAllocatorName));
+    HistogramBase* foo = Histogram::FactoryGet("foo", 1, 100, 10, 0);
+    HistogramBase* bar = Histogram::FactoryGet("bar", 1, 100, 10, 0);
+    foo->Add(42);
+    bar->Add(84);
+
+    scoped_ptr<PersistentMemoryAllocator> allocator(
+        ReleasePersistentHistogramMemoryAllocator());
+    File writer(metrics_file(), File::FLAG_CREATE | File::FLAG_WRITE);
+    EXPECT_TRUE(writer.IsValid());
+    writer.Write(0, (const char*)allocator->data(), allocator->used());
+  }
+
+  ASSERT_TRUE(PathExists(metrics_file()));
+  EXPECT_FALSE(provider()->metrics_found_.load());
+  EXPECT_FALSE(provider()->metrics_file_);
+  provider()->CheckForSetupMetrics();
+  EXPECT_TRUE(provider()->metrics_found_.load());
+  EXPECT_TRUE(provider()->metrics_file_);
+
+  EXPECT_FALSE(provider()->metrics_allocator_);
+  provider()->OnDidCreateMetricsLog();
+  EXPECT_TRUE(provider()->metrics_allocator_);
+  EXPECT_TRUE(provider()->metrics_found_.load());
+  EXPECT_FALSE(provider()->metrics_file_);
+  provider()->OnDidCreateMetricsLog();
+  EXPECT_FALSE(provider()->metrics_allocator_);
+  EXPECT_FALSE(provider()->metrics_found_.load());
+}