[StyleGuide] Allow begin and end non-member functions

base/trace_event/heap_profiler_allocation_context_tracker.cc

 // Copyright 2015 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 "base/trace_event/heap_profiler_allocation_context_tracker.h"
 
 #include <algorithm>
+#include <iterator>
 
 #include "base/atomicops.h"
 #include "base/threading/thread_local_storage.h"
 #include "base/trace_event/heap_profiler_allocation_context.h"
 
 namespace base {
 namespace trace_event {
 
 subtle::Atomic32 AllocationContextTracker::capture_enabled_ = 0;
 
 namespace {
 
 ThreadLocalStorage::StaticSlot g_tls_alloc_ctx_tracker = TLS_INITIALIZER;
 
 // This function is added to the TLS slot to clean up the instance when the
 // thread exits.
 void DestructAllocationContextTracker(void* alloc_ctx_tracker) {
   delete static_cast<AllocationContextTracker*>(alloc_ctx_tracker);
 }
 
-// Returns a pointer past the end of the fixed-size array |array| of |T| of
-// length |N|, identical to C++11 |std::end|.
-template <typename T, int N>
-T* End(T(&array)[N]) {
-  return array + N;
-}
-
 }  // namespace
 
 AllocationContextTracker::AllocationContextTracker() {}
 AllocationContextTracker::~AllocationContextTracker() {}
 
 // static
 AllocationContextTracker* AllocationContextTracker::GetThreadLocalTracker() {
   auto tracker =
       static_cast<AllocationContextTracker*>(g_tls_alloc_ctx_tracker.Get());
 
@@ skipping 47 matching lines @@
 }
 
 // static
 AllocationContext AllocationContextTracker::GetContextSnapshot() {
   AllocationContextTracker* tracker = GetThreadLocalTracker();
   AllocationContext ctx;
 
   // Fill the backtrace.
   {
     auto src = tracker->pseudo_stack_.begin();
-    auto dst = ctx.backtrace.frames;
+    auto dst = std::begin(ctx.backtrace.frames);
     auto src_end = tracker->pseudo_stack_.end();
-    auto dst_end = End(ctx.backtrace.frames);
+    auto dst_end = std::end(ctx.backtrace.frames);
 
     // Copy as much of the bottom of the pseudo stack into the backtrace as
     // possible.
     for (; src != src_end && dst != dst_end; src++, dst++)
       *dst = *src;
 
     // If there is room for more, fill the remaining slots with empty frames.
     std::fill(dst, dst_end, nullptr);
   }
 
   ctx.type_id = 0;
 
   return ctx;
 }
 
 }  // namespace trace_event
 }  // namespace base