Adds support for webrtc::test::ResourcePath on iOS

webrtc/test/testsupport/iosfileutils.mm

+/*
+ *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#if defined(WEBRTC_IOS)
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+#import <Foundation/Foundation.h>
+#include <string.h>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+namespace test {
+
+// TODO(henrika): move to shared location.
+// See https://code.google.com/p/webrtc/issues/detail?id=4773 for details.
+NSString* NSStringFromStdString(const std::string& stdString) {
+  // std::string may contain null termination character so we construct
+  // using length.
+  return [[NSString alloc] initWithBytes:stdString.data()
+                                  length:stdString.length()
+                                encoding:NSUTF8StringEncoding];
+}
+
+std::string StdStringFromNSString(NSString* nsString) {
+  NSData* charData = [nsString dataUsingEncoding:NSUTF8StringEncoding];
+  return std::string(reinterpret_cast<const char*>([charData bytes]),
+                     [charData length]);
+}
+
+// For iOS, resource files are added to the application bundle in the root
+// and not in separate folders as is the case for other platforms. This method
+// therefore removes any prepended folders and uses only the actual file name.
+std::string IOSResourcePath(std::string name, std::string extension) {
+  @autoreleasepool {
+    NSString* path = NSStringFromStdString(name);
+    NSString* fileName = path.lastPathComponent;
+    NSString* fileType = NSStringFromStdString(extension);
+    // Get full pathname for the resource identified by the name and extension.
+    NSString* pathString = [[NSBundle mainBundle] pathForResource:fileName
+                                                           ofType:fileType];
+    return StdStringFromNSString(pathString);
+  }
+}
+
+}  // namespace test
+}  // namespace webrtc
+
+#endif  // defined(WEBRTC_IOS)