Produce more useful stack traces for heap profiling.

base/trace_event/heap_profiler_allocation_context.h

Index: base/trace_event/heap_profiler_allocation_context.h
diff --git a/base/trace_event/heap_profiler_allocation_context.h b/base/trace_event/heap_profiler_allocation_context.h
index 3d8053c9fb31ea3941155d662fcdacfd8e7fe47e..5173eefb3e3689ded124bead115c842b9f3d436b 100644
--- a/base/trace_event/heap_profiler_allocation_context.h
+++ b/base/trace_event/heap_profiler_allocation_context.h
@@ -69,8 +69,8 @@ bool BASE_EXPORT operator != (const StackFrame& lhs, const StackFrame& rhs);
 struct BASE_EXPORT Backtrace {
   Backtrace();
 
-  // If the stack is higher than what can be stored here, the bottom frames
-  // (the ones closer to main()) are stored. Depth of 12 is enough for most
+  // If the stack is higher than what can be stored here, the top frames
+  // (the ones further from main()) are stored. Depth of 12 is enough for most
   // pseudo traces (see above), but not for native traces, where we need more.
   enum { kMaxFrameCount = 48 };
   StackFrame frames[kMaxFrameCount];