Fix incorrect usage of base::EmptyString() in chrome*/.

It is not a general purpose substitute for the default std::string
constructor. Do the same for base::EmptyString16() and base::string16().

Change-Id: I49016d1a97f40818e9387d4cd16e859e19d6eed3
Reviewed-on: https://chromium-review.googlesource.com/c/1295181Reviewed-by: Shu Chen <shuchen@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601871}

chrome/browser/chromeos/arc/intent_helper/open_with_menu.cc

@@ -94,7 +94,7 @@ void OpenWithMenu::ModelChanged(const std::vector<LinkHandlerInfo>& handlers) {
       proxy_->UpdateMenuItem(command_id, true, false, more_apps_label_);
     } else if (it == handlers_.end()) {
       // Hide the menu or submenu parent.
-      proxy_->UpdateMenuItem(command_id, false, true, base::EmptyString16());
+      proxy_->UpdateMenuItem(command_id, false, true, base::string16());
     } else {
       // Update the menu with the new model.
       const base::string16 label = l10n_util::GetStringFUTF16(
@@ -123,14 +123,14 @@ void OpenWithMenu::AddPlaceholderItems(RenderViewContextMenuProxy* proxy,
   for (int i = 0; i < kNumSubMenuCommands; ++i) {
     const int command_id =
         IDC_CONTENT_CONTEXT_OPEN_WITH1 + kNumMainMenuCommands + i;
-    submenu->AddItem(command_id, base::EmptyString16());
+    submenu->AddItem(command_id, base::string16());
   }
   int command_id;
   for (int i = 0; i < kNumMainMenuCommands - 1; ++i) {
     command_id = IDC_CONTENT_CONTEXT_OPEN_WITH1 + i;
-    proxy->AddMenuItem(command_id, base::EmptyString16());
+    proxy->AddMenuItem(command_id, base::string16());
   }
-  proxy->AddSubMenu(++command_id, base::EmptyString16(), submenu);
+  proxy->AddSubMenu(++command_id, base::string16(), submenu);
 }
 
 std::pair<OpenWithMenu::HandlerMap, int> OpenWithMenu::BuildHandlersMap(

chrome/browser/chromeos/arc/intent_helper/start_smart_selection_action_menu.cc

@@ -66,7 +66,7 @@ void StartSmartSelectionActionMenu::InitMenu(
   // Add placeholder items.
   for (size_t i = 0; i < kMaxMainMenuCommands; ++i) {
     proxy_->AddMenuItem(IDC_CONTENT_CONTEXT_START_SMART_SELECTION_ACTION1 + i,
-                        /*title=*/base::EmptyString16());
+                        /*title=*/base::string16());
   }
 }
 

chrome/browser/safe_browsing/test_safe_browsing_service.cc

@@ -15,10 +15,7 @@
 namespace safe_browsing {
 
 // TestSafeBrowsingService functions:
-TestSafeBrowsingService::TestSafeBrowsingService()
-    : SafeBrowsingService(),
-      serialized_download_report_(base::EmptyString()),
-      use_v4_local_db_manager_(false) {
+TestSafeBrowsingService::TestSafeBrowsingService() {
 #if defined(FULL_SAFE_BROWSING)
   services_delegate_ = ServicesDelegate::CreateForTest(this, this);
 #endif  // defined(FULL_SAFE_BROWSING)

chrome/browser/safe_browsing/test_safe_browsing_service.h

@@ -80,14 +80,14 @@ class TestSafeBrowsingService : public SafeBrowsingService,
   std::unique_ptr<V4ProtocolConfig> v4_protocol_config_;
   std::string serialized_download_report_;
   scoped_refptr<SafeBrowsingDatabaseManager> test_database_manager_;
-  bool use_v4_local_db_manager_;
+  bool use_v4_local_db_manager_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(TestSafeBrowsingService);
 };
 
 class TestSafeBrowsingServiceFactory : public SafeBrowsingServiceFactory {
  public:
-  explicit TestSafeBrowsingServiceFactory();
+  TestSafeBrowsingServiceFactory();
   ~TestSafeBrowsingServiceFactory() override;
 
   // Creates test safe browsing service, and configures test UI manager,

chromeos/services/ime/input_engine.cc

@@ -17,10 +17,10 @@ namespace ime {
 namespace {
 
 std::string GetIdFromImeSpec(const std::string& ime_spec) {
-  std::string prefix("m17n:");
-  return base::StartsWith(ime_spec, prefix, base::CompareCase::SENSITIVE)
-             ? ime_spec.substr(prefix.length())
-             : base::EmptyString();
+  static const std::string kPrefix("m17n:");
+  return base::StartsWith(ime_spec, kPrefix, base::CompareCase::SENSITIVE)
+             ? ime_spec.substr(kPrefix.length())
+             : std::string();
 }
 
 }  // namespace
@@ -70,14 +70,14 @@ void InputEngine::ProcessMessage(const std::vector<uint8_t>& message,
   NOTIMPLEMENTED();  // Protobuf message is not used in the rulebased engine.
 }
 
-const std::string InputEngine::Process(const std::string& message,
+std::string InputEngine::Process(const std::string& message,
                                  const InputEngineContext* context) {
   std::string ime_spec = context->ime_spec;
   auto& engine = context->engine;
   if (!engine)
-    return base::EmptyString();
+    return std::string();
 
-  const char* false_response = "{\"result\":false}";
+  const char kFalseResponse[] = "{\"result\":false}";
 
   // The request message is in JSON format as:
   // {
@@ -98,11 +98,11 @@ const std::string InputEngine::Process(const std::string& message,
                                            &error_code, &error_string);
   if (!message_value) {
     LOG(ERROR) << "Read message error: " << error_code << "; " << error_string;
-    return false_response;
+    return kFalseResponse;
   }
   base::Value* method = message_value->FindKey("method");
   if (!method)
-    return false_response;
+    return kFalseResponse;
 
   const std::string& method_str = method->GetString();
   if (method_str == "countKey") {
@@ -117,7 +117,7 @@ const std::string InputEngine::Process(const std::string& message,
   if (method_str == "keyEvent") {
     base::Value* type = message_value->FindKey("type");
     if (!type || type->GetString() != "keydown")
-      return false_response;
+      return kFalseResponse;
   }
 
   base::Value* code = message_value->FindKey("code");
@@ -125,7 +125,7 @@ const std::string InputEngine::Process(const std::string& message,
   base::Value* altgr = message_value->FindKey("altgr");
   base::Value* caps = message_value->FindKey("caps");
   if (!code || !shift || !altgr || !caps)
-    return false_response;
+    return kFalseResponse;
 
   uint8_t modifiers = 0;
   if (shift->GetBool())

chromeos/services/ime/input_engine.h

@@ -17,7 +17,7 @@ class Engine;
 
 class InputEngineContext {
  public:
-  InputEngineContext(const std::string& ime);
+  explicit InputEngineContext(const std::string& ime);
   ~InputEngineContext();
 
   std::string ime_spec;
@@ -52,7 +52,7 @@ class InputEngine : public mojom::InputChannel {
   // TODO(https://crbug.com/837156): Implement a state for the interface.
 
  private:
-  const std::string Process(const std::string& message,
+  std::string Process(const std::string& message,
                       const InputEngineContext* context);
 
   mojo::BindingSet<mojom::InputChannel, std::unique_ptr<InputEngineContext>>