Make most browser accelerators not repeat.

ui/base/accelerators/accelerator_manager.cc

Index: ui/base/accelerators/accelerator_manager.cc
diff --git a/ui/base/accelerators/accelerator_manager.cc b/ui/base/accelerators/accelerator_manager.cc
index fdd2e0aa6344f0a83d4f91249652aa8cc83072fc..d27171bf4c9504548b0a12108b4efb990fd61d13 100644
--- a/ui/base/accelerators/accelerator_manager.cc
+++ b/ui/base/accelerators/accelerator_manager.cc
@@ -25,9 +25,9 @@ void AcceleratorManager::Register(const Accelerator& accelerator,
       << "Registering the same target multiple times";
 
   // All priority accelerators go to the front of the line.
-  if (priority) {
+  if (priority == kHighPriority) {

[Daniel Erat, 2016/07/07 21:08:50]

this isn't exactly related but i saw the old code while i was investigating this
change and it freaked me out. :-P

     DCHECK(!accelerators_[accelerator].first)
-        << "Only one _priority_ handler can be registered";
+        << "Only one high-priority handler can be registered";
     targets.push_front(target);
     // Mark that we have a priority accelerator at the front.
     accelerators_[accelerator].first = true;