Allow whitelisted prefs to be displayed in ChromeOS in chrome://local-state.

chrome/browser/ui/webui/local_state/local_state_ui.cc

 // Copyright 2014 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/ui/webui/local_state/local_state_ui.h"
 
 #include <string>
 
 #include "base/json/json_string_value_serializer.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/url_constants.h"
 #include "components/prefs/pref_service.h"
+#include "components/variations/pref_names.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/browser/web_ui_controller.h"
 #include "content/public/browser/web_ui_data_source.h"
 #include "content/public/browser/web_ui_message_handler.h"
 #include "grit/browser_resources.h"
 
 namespace {
 
 // UI Handler for chrome://local-state. Displays the Local State file as JSON.
 class LocalStateUIHandler : public content::WebUIMessageHandler {
@@ skipping 18 matching lines @@
 LocalStateUIHandler::~LocalStateUIHandler() {
 }
 
 void LocalStateUIHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback(
       "requestJson", base::Bind(&LocalStateUIHandler::HandleRequestJson,
                                 base::Unretained(this)));
 }
 
 void LocalStateUIHandler::HandleRequestJson(const base::ListValue* args) {
-#if !defined(OS_CHROMEOS)
+#if defined(OS_CHROMEOS)
+  std::vector<std::string> whitelisted_prefixes = {
+      "variations", "user_experience_metrics", "uninstall_metrics"};
+  std::unique_ptr<base::DictionaryValue> local_state_values(
+      g_browser_process->local_state()
+          ->GetWhitelistedPreferenceValuesOmitDefaults(whitelisted_prefixes));

[Bernhard Bauer, 2016/04/22 18:24:38]

Couldn't we just do the whitelisting here? We would end up making a couple of
unnecessary copies of the values outside of the whitelist, but it's just for a
debugging page, and we wouldn't be blocking the UI thread for longer than we
would for full GetPreferenceValuesOmitDefaults() anyway.

[hamelphi, 2016/04/22 20:31:28]

I was on the fence between doing the filtering here or in pref_service. I don't
feel strongly one way or another. I moved the filtering here instead.

+#else
   std::unique_ptr<base::DictionaryValue> local_state_values(
       g_browser_process->local_state()->GetPreferenceValuesOmitDefaults());
-
+#endif  // !defined(OS_CHROMEOS)
   std::string json;
   JSONStringValueSerializer serializer(&json);
   serializer.set_pretty_print(true);
   bool result = serializer.Serialize(*local_state_values);
   if (!result)
     json = "Error loading Local State file.";
 
   web_ui()->CallJavascriptFunction("localState.setLocalState",
                                    base::StringValue(json));
-#endif  // !defined(OS_CHROMEOS)
 }
 
 }  // namespace
 
 LocalStateUI::LocalStateUI(content::WebUI* web_ui) : WebUIController(web_ui) {
   // Set up the chrome://local-state source.
   content::WebUIDataSource* html_source =
       content::WebUIDataSource::Create(chrome::kChromeUILocalStateHost);
   html_source->SetDefaultResource(IDR_LOCAL_STATE_HTML);
   html_source->AddResourcePath("local_state.js", IDR_LOCAL_STATE_JS);
   content::WebUIDataSource::Add(Profile::FromWebUI(web_ui), html_source);
 
   // AddMessageHandler takes ownership of LocalStateUIHandler.
   web_ui->AddMessageHandler(new LocalStateUIHandler);
 }
 
 LocalStateUI::~LocalStateUI() {
 }