[wasm] Use a Managed<WasmModule> to hold metadata about modules.

src/wasm/wasm-js.cc

 // Copyright 2015 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/api-natives.h"
 #include "src/api.h"
 #include "src/asmjs/asm-js.h"
 #include "src/asmjs/asm-typer.h"
 #include "src/asmjs/asm-wasm-builder.h"
 #include "src/assert-scope.h"
@@ skipping 86 matching lines @@
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(args.GetIsolate());
   ErrorThrower thrower(isolate, "Wasm.verifyModule()");
 
   if (args.Length() < 1) {
     thrower.TypeError("Argument 0 must be a buffer source");
     return;
   }
   RawBuffer buffer = GetRawBufferSource(args[0], &thrower);
   if (thrower.error()) return;
 
-  i::Zone zone(isolate->allocator(), ZONE_NAME);
-  internal::wasm::ModuleResult result =
-      internal::wasm::DecodeWasmModule(isolate, &zone, buffer.start, buffer.end,
-                                       true, internal::wasm::kWasmOrigin);
+  internal::wasm::ModuleResult result = internal::wasm::DecodeWasmModule(
+      isolate, buffer.start, buffer.end, true, internal::wasm::kWasmOrigin);
 
   if (result.failed()) {
     thrower.CompileFailed("", result);
   }
 
   if (result.val) delete result.val;
 }
 
 void VerifyFunction(const v8::FunctionCallbackInfo<v8::Value>& args) {
   HandleScope scope(args.GetIsolate());
@@ skipping 853 matching lines @@
   if (!memory_object->IsUndefined(isolate)) {
     DCHECK(IsWasmMemoryObject(isolate, memory_object));
     // TODO(gdeepti): This should be a weak list of instance objects
     // for instances that share memory.
     JSObject::cast(*memory_object)
         ->SetInternalField(kWasmMemoryInstanceObject, *instance);
   }
 }
 }  // namespace internal
 }  // namespace v8