[heap] Remove obsolete Heap::sweep_generation field.

src/heap/mark-compact.cc

 // Copyright 2012 the V8 project 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 "src/heap/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 1319 matching lines @@
       // that was not observed by marker.  This might happen if JSRegExp data
       // was marked through the compilation cache before marker reached JSRegExp
       // object.
       FixedArray* data = FixedArray::cast(re->data());
       Object** slot =
           data->data_start() + JSRegExp::saved_code_index(is_one_byte);
       heap->mark_compact_collector()->RecordSlot(data, slot, code);
 
       // Set a number in the 0-255 range to guarantee no smi overflow.
       re->SetDataAt(JSRegExp::code_index(is_one_byte),
-                    Smi::FromInt(heap->sweep_generation() & 0xff));
+                    Smi::FromInt(heap->ms_count() & 0xff));
     } else if (code->IsSmi()) {
       int value = Smi::cast(code)->value();
       // The regexp has not been compiled yet or there was a compilation error.
       if (value == JSRegExp::kUninitializedValue ||
           value == JSRegExp::kCompilationErrorValue) {
         return;
       }
 
       // Check if we should flush now.
-      if (value == ((heap->sweep_generation() - kRegExpCodeThreshold) & 0xff)) {
+      if (value == ((heap->ms_count() - kRegExpCodeThreshold) & 0xff)) {
         re->SetDataAt(JSRegExp::code_index(is_one_byte),
                       Smi::FromInt(JSRegExp::kUninitializedValue));
         re->SetDataAt(JSRegExp::saved_code_index(is_one_byte),
                       Smi::FromInt(JSRegExp::kUninitializedValue));
       }
     }
   }
 
 
   // Works by setting the current sweep_generation (as a smi) in the
@@ skipping 3352 matching lines @@
   SlotsBuffer* buffer = *buffer_address;
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 }  // namespace internal
 }  // namespace v8