Introduce notification_helper_constants.* to improve code consistency

Bug: 734095
Change-Id: Idf5637bb57a7cbfb0b5831cf99e45806d8a9abc6
Reviewed-on: https://chromium-review.googlesource.com/1026972Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Xi Cheng <chengx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553451}

chrome/browser/BUILD.gn

@@ -2925,6 +2925,7 @@ jumbo_split_static_library("browser") {
       "//chrome/common:metrics_constants_util_win",
       "//chrome/common:version_header",
       "//chrome/install_static:install_static_util",
+      "//chrome/notification_helper:constants",
       "//chrome/services/util_win/public/mojom",
       "//chrome_elf:blacklist",
       "//chrome_elf:constants",

chrome/browser/DEPS

@@ -6,6 +6,7 @@ include_rules = [
   "+chrome/grit",
   "+chrome/install_static",
   "+chrome/installer/util",
+  "+chrome/notification_helper/notification_helper_constants.h",
   "+chrome/services/file_util/public",
   "+chrome/services/media_gallery_util/public",
   "+chrome/services/printing/public",

chrome/browser/metrics/chrome_metrics_service_client.cc

@@ -134,6 +134,7 @@
 #include "chrome/browser/metrics/google_update_metrics_provider_win.h"
 #include "chrome/common/metrics_constants_util_win.h"
 #include "chrome/install_static/install_util.h"
+#include "chrome/notification_helper/notification_helper_constants.h"
 #include "components/browser_watcher/watcher_metrics_provider_win.h"
 #endif
 
@@ -166,13 +167,6 @@ const int kMaxHistogramGatheringWaitDuration = 60000;  // 60 seconds.
 // third_party/crashpad/crashpad/handler/handler_main.cc.
 const char kCrashpadHistogramAllocatorName[] = "CrashpadMetrics";
 
-#if defined(OS_WIN)
-// Must be kept in sync with the allocator name in
-// notification_helper/notification_helper.cc.
-constexpr char kNotificationHelperHistogramAllocatorName[] =
-    "NotificationHelperMetrics";
-#endif
-
 #if defined(OS_WIN) || defined(OS_MACOSX)
 // The stream type assigned to the minidump stream that holds the serialized
 // system profile proto.
@@ -198,7 +192,7 @@ void RegisterFileMetricsPreferences(PrefRegistrySimple* registry) {
       registry, installer::kSetupHistogramAllocatorName);
 
   metrics::FileMetricsProvider::RegisterPrefs(
-      registry, kNotificationHelperHistogramAllocatorName);
+      registry, notification_helper::kNotificationHelperHistogramAllocatorName);
 #endif
 }
 
@@ -306,7 +300,8 @@ std::unique_ptr<metrics::FileMetricsProvider> CreateFileMetricsProvider(
   // potential duplicate code.
   if (!user_data_dir.empty()) {
     base::FilePath notification_helper_metrics_upload_dir =
-        user_data_dir.AppendASCII(kNotificationHelperHistogramAllocatorName);
+        user_data_dir.AppendASCII(
+            notification_helper::kNotificationHelperHistogramAllocatorName);
 
     if (metrics_reporting_enabled) {
       file_metrics_provider->RegisterSource(
@@ -314,7 +309,7 @@ std::unique_ptr<metrics::FileMetricsProvider> CreateFileMetricsProvider(
               notification_helper_metrics_upload_dir,
               metrics::FileMetricsProvider::SOURCE_HISTOGRAMS_ATOMIC_DIR,
               metrics::FileMetricsProvider::ASSOCIATE_CURRENT_RUN,
-              kNotificationHelperHistogramAllocatorName));
+              notification_helper::kNotificationHelperHistogramAllocatorName));
     } else {
       base::PostTaskWithTraits(
           FROM_HERE,

chrome/notification_helper/BUILD.gn

@@ -18,6 +18,7 @@ executable("notification_helper") {
   configs += [ "//build/config/win:windowed" ]
 
   deps = [
+    ":constants",
     ":lib",
     ":version_resources",
     "//base",
@@ -52,6 +53,13 @@ source_set("lib") {
   ]
 }
 
+source_set("constants") {
+  sources = [
+    "notification_helper_constants.cc",
+    "notification_helper_constants.h",
+  ]
+}
+
 process_version_rc_template("version_resources") {
   sources = [
     "notification_helper_exe.ver",

chrome/notification_helper/notification_helper.cc

@@ -16,6 +16,7 @@
 #include "chrome/install_static/product_install_details.h"
 #include "chrome/install_static/user_data_dir.h"
 #include "chrome/notification_helper/com_server_module.h"
+#include "chrome/notification_helper/notification_helper_constants.h"
 #include "chrome/notification_helper/notification_helper_crash_reporter_client.h"
 #include "chrome/notification_helper/notification_helper_util.h"
 #include "chrome/notification_helper/trace_util.h"
@@ -25,10 +26,8 @@ extern "C" int WINAPI wWinMain(HINSTANCE instance,
                                wchar_t* command_line,
                                int show_command) {
   // Persist histograms so they can be uploaded later.
-  // The allocator name must be kept in sync with the writer in
-  // chrome/browser/metrics/chrome_metrics_service_client.cc.
   base::PersistentHistogramStorage persistent_histogram_storage(
-      "NotificationHelperMetrics",
+      notification_helper::kNotificationHelperHistogramAllocatorName,
       base::PersistentHistogramStorage::StorageDirManagement::kCreate);
 
   // Initialize the CommandLine singleton from the environment.

chrome/notification_helper/notification_helper_constants.cc

+// Copyright 2018 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/notification_helper/notification_helper_constants.h"
+
+namespace notification_helper {
+
+const char kNotificationHelperHistogramAllocatorName[] =
+    "NotificationHelperMetrics";
+
+}  // namespace notification_helper

chrome/notification_helper/notification_helper_constants.h

+// Copyright 2018 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.
+
+#ifndef CHROME_NOTIFICATION_HELPER_NOTIFICATION_HELPER_CONSTANTS_H_
+#define CHROME_NOTIFICATION_HELPER_NOTIFICATION_HELPER_CONSTANTS_H_
+
+namespace notification_helper {
+
+extern const char kNotificationHelperHistogramAllocatorName[];
+
+}  // namespace notification_helper
+
+#endif  // CHROME_NOTIFICATION_HELPER_NOTIFICATION_HELPER_CONSTANTS_H_