Reland "Implement Math.random() purely in JavaScript" plus fixes.

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 676 matching lines @@
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSProxy, proxy, 0);
   JSProxy::Fix(proxy);
   return isolate->heap()->undefined_value();
 }
 
 
 void Runtime::FreeArrayBuffer(Isolate* isolate,
                               JSArrayBuffer* phantom_array_buffer) {
+  if (phantom_array_buffer->should_be_freed()) {
+    free(phantom_array_buffer->backing_store());

[Yang, 2013/11/22 11:34:43]

Please make sure that this returns afterwards, either by asserting that
should_be_freed() also implies is_external(), or just adding a return right
after. This would prevent freeing again using the allocator later.

+  }
   if (phantom_array_buffer->is_external()) return;
 
   size_t allocated_length = NumberToSize(
       isolate, phantom_array_buffer->byte_length());
 
   isolate->heap()->AdjustAmountOfExternalAllocatedMemory(
       -static_cast<int64_t>(allocated_length));
   CHECK(V8::ArrayBufferAllocator() != NULL);
   V8::ArrayBufferAllocator()->Free(
       phantom_array_buffer->backing_store(),
@@ skipping 14181 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal