Keep per-app GUID for WebView Metrics

android_webview/browser/aw_browser_context.cc

 // Copyright (c) 2012 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 "android_webview/browser/aw_browser_context.h"
 
 #include <utility>
 
 #include "android_webview/browser/aw_browser_policy_connector.h"
 #include "android_webview/browser/aw_form_database_service.h"
@@ skipping 238 matching lines @@
 
   // TODO(dgn) lazy init, see http://crbug.com/521542
   data_reduction_proxy_settings_->InitDataReductionProxySettings(
       kDataReductionProxyEnabled, user_pref_service_.get(),
       data_reduction_proxy_io_data_.get(),
       std::move(data_reduction_proxy_service_));
   data_reduction_proxy_settings_->MaybeActivateDataReductionProxy(true);
 
   blacklist_manager_.reset(CreateURLBlackListManager(user_pref_service_.get()));
 
+  // UMA uses randomly-generated GUIDs (globally unique identifiers) to
+  // anonymously identify logs. Every WebView-using app on every device
+  // is given a GUID, stored in this file in the app's data directory.
+  const FilePath guid_file_path =
+      GetPath().Append(FILE_PATH_LITERAL("metrics_guid"));
+
   AwMetricsServiceClient::GetInstance()->Initialize(user_pref_service_.get(),
-                                                    GetRequestContext());
+                                                    GetRequestContext(),
+                                                    guid_file_path);
 }
 
 void AwBrowserContext::PostMainMessageLoopRun() {
   AwMetricsServiceClient::GetInstance()->Finalize();
 }
 
 void AwBrowserContext::AddVisitedURLs(const std::vector<GURL>& urls) {
   DCHECK(visitedlink_master_);
   visitedlink_master_->AddURLs(urls);
 }
@@ skipping 200 matching lines @@
     return;
   // We don't care about commit_delay for now. It is just a dummy value.
   base::TimeDelta commit_delay = base::TimeDelta::FromMinutes(60);
   data_reduction_proxy_service->EnableCompressionStatisticsLogging(
       user_pref_service_.get(),
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI),
       commit_delay);
 }
 
 }  // namespace android_webview