Add frame-specific InterfaceProviderSpec.

services/service_manager/public/cpp/lib/interface_provider_spec.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 "services/service_manager/public/cpp/interface_provider_spec.h"
 
 #include <tuple>
 
+#include "base/logging.h"
+
 namespace service_manager {
 
 InterfaceProviderSpec::InterfaceProviderSpec() {}
 InterfaceProviderSpec::InterfaceProviderSpec(
     const InterfaceProviderSpec& other) = default;
 InterfaceProviderSpec::~InterfaceProviderSpec() {}
 
 bool InterfaceProviderSpec::operator==(
     const InterfaceProviderSpec& other) const {
   return other.provides == provides && other.requires == requires;
 }
 
 bool InterfaceProviderSpec::operator<(
     const InterfaceProviderSpec& other) const {
   return std::tie(provides, requires) <
       std::tie(other.provides, other.requires);
 }
 
+bool GetInterfaceProviderSpec(const std::string& spec_name,
+                              const InterfaceProviderSpecMap& map,
+                              InterfaceProviderSpec* spec) {
+  DCHECK(spec);
+  auto it = map.find(spec_name);
+  if (it != map.end()) {
+    *spec = it->second;
+    return true;
+  }
+  return false;
+}
+
 }  // namespace service_manager