Add has_value() and value() methods to rtc::Optional.

webrtc/base/optional.h

 /*
  *  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.
  */
 
@@ skipping 200 matching lines @@
     if (has_value_)
       value_.~T();
     else
       UnpoisonValue();
     new (&value_) T(std::forward<Args>(args)...);
     has_value_ = true;
   }
 
   // Conversion to bool to test if we have a value.
   explicit operator bool() const { return has_value_; }
+  bool has_value() const { return has_value_; }
 
   // Dereferencing. Only allowed if we have a value.
   const T* operator->() const {
     RTC_DCHECK(has_value_);
     return &value_;
   }
   T* operator->() {
     RTC_DCHECK(has_value_);
     return &value_;
   }
   const T& operator*() const {
     RTC_DCHECK(has_value_);
     return value_;
   }
   T& operator*() {
     RTC_DCHECK(has_value_);
     return value_;
   }
+  const T& value() const {
+    RTC_DCHECK(has_value_);
+    return value_;
+  }
+  T& value() {
+    RTC_DCHECK(has_value_);
+    return value_;
+  }
 
   // Dereference with a default value in case we don't have a value.
   const T& value_or(const T& default_val) const {
     // The no-op call prevents the compiler from generating optimized code that
     // reads value_ even if !has_value_, but only if FunctionThatDoesNothing is
     // not completely inlined; see its declaration.).
     return has_value_ ? *optional_internal::FunctionThatDoesNothing(&value_)
                       : default_val;
   }
 
@@ skipping 142 matching lines @@
   } else {
     *os << "<empty optional>";
   }
 }
 
 #endif  // UNIT_TEST
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_OPTIONAL_H_