Align base::Pickle allocations to 4k boundaries

base/trace_event/trace_event_memory_overhead.cc

Index: base/trace_event/trace_event_memory_overhead.cc
diff --git a/base/trace_event/trace_event_memory_overhead.cc b/base/trace_event/trace_event_memory_overhead.cc
index 5ece315c00f30485ee0dce9c997b83de6007f3ee..243d007ea654310f6188cd46cd32eb6a9e124c47 100644
--- a/base/trace_event/trace_event_memory_overhead.cc
+++ b/base/trace_event/trace_event_memory_overhead.cc
@@ -6,18 +6,13 @@
 
 #include <algorithm>
 
+#include "base/bits.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "base/values.h"
 
-namespace {
-size_t RoundUp(size_t size, size_t alignment) {
-  return (size + alignment - 1) & ~(alignment - 1);
-}
-}  // namespace
-
 namespace base {
 namespace trace_event {
 
@@ -62,8 +57,8 @@ void TraceEventMemoryOverhead::AddString(const std::string& str) {
   // std::string implementations:
   //  - even short string end up malloc()-inc at least 32 bytes.
   //  - longer stings seem to malloc() multiples of 16 bytes.

[Lei Zhang, 2015/07/24 01:36:48]

BTW, typo: "stings"

[Primiano Tucci (use gerrit), 2015/07/24 09:37:38]

Ah, thanks

-  Add("std::string",
-      sizeof(std::string) + std::max<size_t>(RoundUp(str.capacity(), 16), 32u));
+  const size_t capacity = bits::Align(str.capacity(), 16);
+  Add("std::string", sizeof(std::string) + std::max<size_t>(capacity, 32u));
 }
 
 void TraceEventMemoryOverhead::AddRefCountedString(