Use V8 Maybe APIs in extensions/renderer

extensions/renderer/i18n_custom_bindings.cc

Index: extensions/renderer/i18n_custom_bindings.cc
diff --git a/extensions/renderer/i18n_custom_bindings.cc b/extensions/renderer/i18n_custom_bindings.cc
index 762627088ef020edda6d8603b421177df45da93a..0ba18c208e06e1c468a0ebd8d68870af2d5a593c 100644
--- a/extensions/renderer/i18n_custom_bindings.cc
+++ b/extensions/renderer/i18n_custom_bindings.cc
@@ -10,6 +10,7 @@
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/message_bundle.h"
 #include "extensions/renderer/script_context.h"
+#include "extensions/renderer/v8_maybe_helpers.h"
 
 namespace extensions {
 
@@ -73,22 +74,28 @@ void I18NCustomBindings::GetL10nMessage(
     if (count > 9)
       return;
     for (uint32_t i = 0; i < count; ++i) {
-      substitutions.push_back(*v8::String::Utf8Value(placeholders->Get(
-          v8::Integer::New(isolate, i))));
+      v8::Local<v8::Value> param;
+      if (!placeholders->Get(isolate->GetCurrentContext(),
+                             v8::Integer::New(isolate, i))
+               .ToLocal(&param))
+        return;
+      substitutions.push_back(*v8::String::Utf8Value(param));
     }
   } else if (args[1]->IsString()) {
     // chrome.i18n.getMessage("message_name", "one param");
     substitutions.push_back(*v8::String::Utf8Value(args[1]));
   }
 
-  args.GetReturnValue().Set(v8::String::NewFromUtf8(
-      isolate,
-      ReplaceStringPlaceholders(message, substitutions, NULL).c_str()));
+  std::string ret_value =
+      ReplaceStringPlaceholders(message, substitutions, NULL);
+  if (ret_value.size() >= v8::String::kMaxLength)
+    return;
+  args.GetReturnValue().Set(ToV8String(isolate, ret_value.c_str()));
 }
 
 void I18NCustomBindings::GetL10nUILanguage(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
-  args.GetReturnValue().Set(v8::String::NewFromUtf8(
+  args.GetReturnValue().Set(ToV8String(
       args.GetIsolate(), content::RenderThread::Get()->GetLocale().c_str()));
 }