arc: Provide a per-service getter for ArcServiceManager

components/arc/arc_service_manager.cc

Index: components/arc/arc_service_manager.cc
diff --git a/components/arc/arc_service_manager.cc b/components/arc/arc_service_manager.cc
index 9204fef44844ccd7fc9ea29da2e6ba91aaba29fe..e4911e8a9157b8cc34c2c126af56dc171a0e8d49 100644
--- a/components/arc/arc_service_manager.cc
+++ b/components/arc/arc_service_manager.cc
@@ -4,8 +4,6 @@
 
 #include "components/arc/arc_service_manager.h"
 
-#include <utility>
-
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/task_runner.h"
@@ -75,11 +73,28 @@ ArcBridgeService* ArcServiceManager::arc_bridge_service() {
   return arc_bridge_service_.get();
 }
 
-void ArcServiceManager::AddService(std::unique_ptr<ArcService> service) {
+void ArcServiceManager::AddServiceInternal(
+    std::unique_ptr<ArcService> service) {
   DCHECK(thread_checker_.CalledOnValidThread());
   services_.emplace_back(std::move(service));
 }
 
+void ArcServiceManager::AddNamedServiceInternal(
+    const std::string& name,
+    std::unique_ptr<ArcService> service) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(named_services_.find(name) == named_services_.end());

[Yusuke Sato, 2017/01/10 07:11:10]

What about making this a CHECK? Otherwise, L87 will be just no-op on production
when two or more services have the same name, and such a mistake may be
difficult to find/debug.

  DCHECK(thread_checker_.CalledOnValidThread());
  const bool result = named_services_.insert(std::make_pair(name,
std::move(service))).second;
  CHECK(result) << name << " is used twice";
 }

[Luis Héctor Chávez, 2017/01/10 18:41:55]

CHECKs are frowned upon outside of base/. I will add some logging, though.

+  named_services_.insert(std::make_pair(name, std::move(service)));

[hidehiko, 2017/01/10 08:03:12]

emplace?

[Luis Héctor Chávez, 2017/01/10 18:41:55]

emplace is not supported for maps:
https://chromium-cpp.appspot.com/#library-whitelist

[hidehiko, 2017/01/11 05:17:44]

Oh, good to know. Thank you!

+}
+
+ArcService* ArcServiceManager::GetNamedServiceInternal(
+    const std::string& name) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  auto service = named_services_.find(name);
+  DCHECK(service != named_services_.end());
+  return service->second.get();
+}
+
 void ArcServiceManager::AddObserver(Observer* observer) {
   DCHECK(thread_checker_.CalledOnValidThread());
   observer_list_.AddObserver(observer);
@@ -100,6 +115,7 @@ void ArcServiceManager::Shutdown() {
   icon_loader_ = nullptr;
   activity_resolver_ = nullptr;
   services_.clear();
+  named_services_.clear();
 }
 
 }  // namespace arc