Update API for Objective-C RTCMediaConstraints.

BUG=

Review URL: https://codereview.webrtc.org/1543033003

Cr-Commit-Position: refs/heads/master@{#11172}

webrtc/api/objctests/RTCMediaConstraintsTest.mm

@@ -0,0 +1,66 @@
+/*
+ *  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.
+ */
+
+#import <Foundation/Foundation.h>
+
+#include "webrtc/base/gunit.h"
+
+#import "webrtc/api/objc/RTCMediaConstraints.h"
+#import "webrtc/api/objc/RTCMediaConstraints+Private.h"
+#import "webrtc/base/objc/NSString+StdString.h"
+
+@interface RTCMediaConstraintsTest : NSObject
+- (void)testMediaConstraints;
+@end
+
+@implementation RTCMediaConstraintsTest
+
+- (void)testMediaConstraints {
+  NSDictionary *mandatory = @{@"key1": @"value1", @"key2": @"value2"};
+  NSDictionary *optional = @{@"key3": @"value3", @"key4": @"value4"};
+
+  RTCMediaConstraints *constraints = [[RTCMediaConstraints alloc]
+      initWithMandatoryConstraints:mandatory
+               optionalConstraints:optional];
+  rtc::scoped_ptr<webrtc::MediaConstraints> nativeConstraints =
+      [constraints nativeConstraints];
+
+  webrtc::MediaConstraintsInterface::Constraints nativeMandatory =
+      nativeConstraints->GetMandatory();
+  [self expectConstraints:mandatory inNativeConstraints:nativeMandatory];
+
+  webrtc::MediaConstraintsInterface::Constraints nativeOptional =
+      nativeConstraints->GetOptional();
+  [self expectConstraints:optional inNativeConstraints:nativeOptional];
+}
+
+- (void)expectConstraints:(NSDictionary *)constraints
+      inNativeConstraints:
+    (webrtc::MediaConstraintsInterface::Constraints)nativeConstraints {
+  EXPECT_EQ(constraints.count, nativeConstraints.size());
+
+  for (NSString *key in constraints) {
+    NSString *value = constraints[key];
+
+    std::string nativeValue;
+    bool found = nativeConstraints.FindFirst(key.stdString, &nativeValue);
+    EXPECT_TRUE(found);
+    EXPECT_EQ(value.stdString, nativeValue);
+  }
+}
+
+@end
+
+TEST(RTCMediaConstraintsTest, MediaConstraintsTest) {
+  @autoreleasepool {
+    RTCMediaConstraintsTest *test = [[RTCMediaConstraintsTest alloc] init];
+    [test testMediaConstraints];
+  }
+}