[Extensions] Add metrics for extension initialization

extensions/common/extension.cc

 // Copyright (c) 2013 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 "extensions/common/extension.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
 
 #include "base/base64.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/memory/singleton.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/stl_util.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/timer/elapsed_timer.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "components/crx_file/id_util.h"
+#include "content/public/common/content_switches.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/feature_switch.h"
 #include "extensions/common/manifest.h"
 #include "extensions/common/manifest_constants.h"
 #include "extensions/common/manifest_handler.h"
 #include "extensions/common/manifest_handlers/incognito_info.h"
 #include "extensions/common/manifest_handlers/permissions_parser.h"
 #include "extensions/common/permissions/permission_set.h"
@@ skipping 71 matching lines @@
 }
 
 // TODO(sungguk): Continue removing std::string errors and replacing
 // with base::string16. See http://crbug.com/71980.
 scoped_refptr<Extension> Extension::Create(const base::FilePath& path,
                                            Manifest::Location location,
                                            const base::DictionaryValue& value,
                                            int flags,
                                            const std::string& explicit_id,
                                            std::string* utf8_error) {
+  base::ElapsedTimer timer;
   DCHECK(utf8_error);
   base::string16 error;
   std::unique_ptr<extensions::Manifest> manifest(new extensions::Manifest(
       location, std::unique_ptr<base::DictionaryValue>(value.DeepCopy())));
 
   if (!InitExtensionID(manifest.get(), path, explicit_id, flags, &error)) {
     *utf8_error = base::UTF16ToUTF8(error);
     return NULL;
   }
 
   std::vector<InstallWarning> install_warnings;
   if (!manifest->ValidateManifest(utf8_error, &install_warnings)) {
     return NULL;
   }
 
   scoped_refptr<Extension> extension = new Extension(path, std::move(manifest));
   extension->install_warnings_.swap(install_warnings);
 
   if (!extension->InitFromValue(flags, &error)) {
     *utf8_error = base::UTF16ToUTF8(error);
     return NULL;
   }
 
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+  std::string process_type =
+      command_line.GetSwitchValueASCII(::switches::kProcessType);
+  // Use microsecond accuracy for increased granularity. Max at 10 seconds.
+  base::TimeDelta elapsed_time = timer.Elapsed();
+  const int kMaxTimeInMicroseconds = 10000000;
+  if (process_type.empty()) {
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "Extensions.ExtensionCreationTime.BrowserProcess",
+        elapsed_time.InMicroseconds(), 1, kMaxTimeInMicroseconds, 100);
+  } else if (command_line.HasSwitch(switches::kExtensionProcess)) {
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "Extensions.ExtensionCreationTime.ExtensionProcess",
+        elapsed_time.InMicroseconds(), 1, kMaxTimeInMicroseconds, 100);
+  } else if (process_type == ::switches::kRendererProcess) {
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "Extensions.ExtensionCreationTime.RendererProcess",
+        elapsed_time.InMicroseconds(), 1, kMaxTimeInMicroseconds, 100);
+  }
+
   return extension;
 }
 
 Manifest::Type Extension::GetType() const {
   return converted_from_user_script() ?
       Manifest::TYPE_USER_SCRIPT : manifest_->type();
 }
 
 // static
 GURL Extension::GetResourceURL(const GURL& extension_url,
@@ skipping 624 matching lines @@
     : reason(reason),
       extension(extension) {}
 
 UpdatedExtensionPermissionsInfo::UpdatedExtensionPermissionsInfo(
     const Extension* extension,
     const PermissionSet& permissions,
     Reason reason)
     : reason(reason), extension(extension), permissions(permissions) {}
 
 }   // namespace extensions