[Extensions Bindings] Fix getPlatform() method

extensions/renderer/bindings/api_binding.cc

 // Copyright 2016 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/renderer/bindings/api_binding.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "extensions/renderer/bindings/api_binding_hooks.h"
 #include "extensions/renderer/bindings/api_binding_types.h"
+#include "extensions/renderer/bindings/api_binding_util.h"
 #include "extensions/renderer/bindings/api_event_handler.h"
 #include "extensions/renderer/bindings/api_invocation_errors.h"
 #include "extensions/renderer/bindings/api_request_handler.h"
 #include "extensions/renderer/bindings/api_signature.h"
 #include "extensions/renderer/bindings/api_type_reference_map.h"
 #include "extensions/renderer/bindings/binding_access_checker.h"
 #include "extensions/renderer/bindings/declarative_event.h"
 #include "gin/arguments.h"
 #include "gin/handle.h"
 #include "gin/per_context_data.h"
 #include "third_party/WebKit/public/web/WebUserGestureIndicator.h"
 
 namespace extensions {
 
 namespace {
 
-std::string GetPlatformString() {
-#if defined(OS_CHROMEOS)
-  return "chromeos";
-#elif defined(OS_LINUX)
-  return "linux";
-#elif defined(OS_MACOSX)
-  return "mac";
-#elif defined(OS_WIN)
-  return "win";
-#else
-  NOTREACHED();
-  return std::string();
-#endif
-}
-
 // Returns the name of the enum value for use in JavaScript; JS enum entries use
 // SCREAMING_STYLE.
 std::string GetJSEnumEntryName(const std::string& original) {
   // The webstorePrivate API has an empty enum value for a result.
   // TODO(devlin): Work with the webstore team to see if we can move them off
   // this - they also already have a "success" result that they can use.
   // See crbug.com/709120.
   if (original.empty())
     return original;
 
@@ skipping 387 matching lines @@
 
     const base::ListValue* platforms = nullptr;
     // TODO(devlin): This isn't great. It's bad to have availability primarily
     // defined in the features files, and then partially defined within the
     // API specification itself. Additionally, they aren't equivalent
     // definitions. But given the rarity of property restrictions, and the fact
     // that they are all limited by platform, it makes more sense to isolate
     // this check here. If this becomes more common, we should really find a
     // way of moving these checks to the features files.
     if (dict->GetList("platforms", &platforms)) {
-      std::string this_platform = GetPlatformString();
+      std::string this_platform = binding::GetPlatformString();
       auto is_this_platform = [&this_platform](const base::Value& platform) {
         return platform.is_string() && platform.GetString() == this_platform;
       };
       if (std::none_of(platforms->begin(), platforms->end(), is_this_platform))
         continue;
     }
 
     v8::Local<v8::String> v8_key = gin::StringToSymbol(isolate, iter.key());
     std::string ref;
     if (dict->GetString("$ref", &ref)) {
@@ skipping 188 matching lines @@
     arguments->ThrowTypeError(api_errors::InvocationError(
         name, signature->GetExpectedSignature(), error));
     return;
   }
 
   request_handler_->StartRequest(context, name, std::move(converted_arguments),
                                  callback, custom_callback, thread);
 }
 
 }  // namespace extensions