Revert of Cleaner fall-back stack capture for --enable-heap-profiling=native.

base/trace_event/heap_profiler_allocation_context_tracker.cc

Index: base/trace_event/heap_profiler_allocation_context_tracker.cc
diff --git a/base/trace_event/heap_profiler_allocation_context_tracker.cc b/base/trace_event/heap_profiler_allocation_context_tracker.cc
index 6b7383e2cbfee98c472317e5cf0028f691cc3caf..b47dc16eddd02b2565bd18511d0490a17c488056 100644
--- a/base/trace_event/heap_profiler_allocation_context_tracker.cc
+++ b/base/trace_event/heap_profiler_allocation_context_tracker.cc
@@ -203,34 +203,30 @@
         // from main() and up. Stack unwinding produces top frames, i.e.
         // from this point and up until main(). We request many frames to
         // make sure we reach main(), and then copy bottom portion of them.
-#if !defined(OS_NACL)  // We don't build base/debug/stack_trace.cc for NaCl.
-#if HAVE_TRACE_STACK_FRAME_POINTERS
-      const void* frames[128];
-      static_assert(arraysize(frames) >= Backtrace::kMaxFrameCount,
-                    "not requesting enough frames to fill Backtrace");
-      size_t frame_count = debug::TraceStackFramePointers(
-          frames, arraysize(frames),
-          1 /* exclude this function from the trace */);
-#else   // HAVE_TRACE_STACK_FRAME_POINTERS
-      // Fall-back to capturing the stack with base::debug::StackTrace,
-      // which is likely slower, but more reliable.
-      base::debug::StackTrace stack_trace(Backtrace::kMaxFrameCount);
-      size_t frame_count = 0u;
-      const void* const* frames = stack_trace.Addresses(&frame_count);
-#endif  // HAVE_TRACE_STACK_FRAME_POINTERS
-
-      // Copy frames backwards
-      size_t backtrace_capacity = backtrace_end - backtrace;
-      int32_t top_frame_index = (backtrace_capacity >= frame_count)
-                                    ? 0
-                                    : frame_count - backtrace_capacity;
-      for (int32_t i = frame_count - 1; i >= top_frame_index; --i) {
-        const void* frame = frames[i];
-        *backtrace++ = StackFrame::FromProgramCounter(frame);
+        const void* frames[128];
+        static_assert(arraysize(frames) >= Backtrace::kMaxFrameCount,
+                      "not requesting enough frames to fill Backtrace");
+#if HAVE_TRACE_STACK_FRAME_POINTERS && !defined(OS_NACL)
+        size_t frame_count = debug::TraceStackFramePointers(
+            frames,
+            arraysize(frames),
+            1 /* exclude this function from the trace */ );
+#else
+        size_t frame_count = 0;
+        NOTREACHED();
+#endif
+
+        // Copy frames backwards
+        size_t backtrace_capacity = backtrace_end - backtrace;
+        int32_t top_frame_index = (backtrace_capacity >= frame_count)
+                                      ? 0
+                                      : frame_count - backtrace_capacity;
+        for (int32_t i = frame_count - 1; i >= top_frame_index; --i) {
+          const void* frame = frames[i];
+          *backtrace++ = StackFrame::FromProgramCounter(frame);
+        }
+        break;
       }
-#endif  // !defined(OS_NACL)
-      break;
-    }
   }
 
   ctx->backtrace.frame_count = backtrace - std::begin(ctx->backtrace.frames);