Make mash register initial batch of accelerators in single shot.

ash/common/accelerators/accelerator_controller.cc

Index: ash/common/accelerators/accelerator_controller.cc
diff --git a/ash/common/accelerators/accelerator_controller.cc b/ash/common/accelerators/accelerator_controller.cc
index db032bb3a8cafe407d68f3628775a7d7165a25af..3865444c0a7a92c0eefb3452eb66a48458cb391f 100644
--- a/ash/common/accelerators/accelerator_controller.cc
+++ b/ash/common/accelerators/accelerator_controller.cc
@@ -559,6 +559,11 @@ void AcceleratorController::Register(const ui::Accelerator& accelerator,
       accelerator, ui::AcceleratorManager::kNormalPriority, target);
 }
 
+void AcceleratorController::Registers(
+    std::vector<ui::Accelerator>& ui_accelerators) {
+  accelerator_manager_->Registers(ui_accelerators);
+}
+
 void AcceleratorController::Unregister(const ui::Accelerator& accelerator,
                                        ui::AcceleratorTarget* target) {
   accelerator_manager_->Unregister(accelerator, target);
@@ -750,13 +755,16 @@ void AcceleratorController::Init() {
 void AcceleratorController::RegisterAccelerators(
     const AcceleratorData accelerators[],
     size_t accelerators_length) {
+  std::vector<ui::Accelerator> ui_accelerators;
   for (size_t i = 0; i < accelerators_length; ++i) {
     ui::Accelerator accelerator =
         CreateAccelerator(accelerators[i].keycode, accelerators[i].modifiers,
                           accelerators[i].trigger_on_press);
     Register(accelerator, this);

[mfomitchev, 2016/12/20 03:10:26]

I am not sure what are you trying to do here. You are calling both Register()
and Registers() which doesn't make much sense. 

I wouldn't add Registers() at all, because I don't think it's going to help
much. I'd just call accelerator_manager_->Register() and pass it an array of
accelerators along with target and priority (this implies we either overload the
existing Register method in AcceleratorManager or rewrite it to always accept an
array). Note that the target and priority are all the same, so it might make
sense to take advantage of this: instead of passing an array of 3-element sets
{accelerator, priority, target}, you can pass an array of accelerators, plus the
target and the priority which these accelerators all share.

[thanhph, 2016/12/20 20:46:14]

Thanks. I go with the approach "pass an array of accelerators, plus the target
and the priority which these accelerators all share."

+    ui_accelerators.push_back(accelerator);
     accelerators_.insert(std::make_pair(accelerator, accelerators[i].action));
   }
+  Registers(ui_accelerators);
 }
 
 void AcceleratorController::RegisterDeprecatedAccelerators() {