Add Equals() to mojom structs and related types.

mojo/public/cpp/bindings/map.h

 // Copyright 2014 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_MAP_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_MAP_H_
 
 #include <map>
 
 #include "mojo/public/cpp/bindings/lib/map_internal.h"
@@ skipping 99 matching lines @@
   // Please note that calling this method will fail compilation if the value
   // type cannot be cloned (which usually means that it is a Mojo handle type or
   // a type contains Mojo handles).
   Map Clone() const {
     Map result;
     result.is_null_ = is_null_;
     Traits::Clone(map_, &result.map_);
     return result.Pass();
   }
 
+  bool Equals(const Map& other) const {
+    if (is_null() != other.is_null())
+      return false;
+    if (size() != other.size())
+      return false;
+    auto i = begin();
+    auto j = other.begin();
+    while (i != end()) {
+      if (i.GetKey() != j.GetKey())
+        return false;
+      if (!internal::ValueTraits<Value>::Equals(i.GetValue(), j.GetValue()))
+        return false;
+      ++i;
+      ++j;
+    }
+    return true;
+  }
+
   class ConstMapIterator {
    public:
     ConstMapIterator(
         const typename std::map<KeyStorageType,
                                 ValueStorageType>::const_iterator& it)
         : it_(it) {}
 
     KeyConstRefType GetKey() { return Traits::GetKey(it_); }
     ValueConstRefType GetValue() { return Traits::GetValue(it_); }
 
@@ skipping 68 matching lines @@
             TypeConverter<STLValue, MojoValue>::Convert(it.GetValue())));
       }
     }
     return result;
   }
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_MAP_H_