[Extensions] Don't allow gin::Define to be overridden

extensions/renderer/blob_native_handler.cc

 // Copyright 2014 The Chromium 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 "extensions/renderer/blob_native_handler.h"
 
 #include "base/bind.h"
 #include "extensions/renderer/script_context.h"
 #include "third_party/WebKit/public/platform/WebCString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/web/WebBlob.h"
 
 namespace {
 
 // Expects a single Blob argument. Returns the Blob's UUID.
 void GetBlobUuid(const v8::FunctionCallbackInfo<v8::Value>& args) {
-  DCHECK_EQ(1, args.Length());
+  CHECK_EQ(1, args.Length());
   blink::WebBlob blob = blink::WebBlob::fromV8Value(args[0]);
   args.GetReturnValue().Set(
       v8::String::NewFromUtf8(args.GetIsolate(), blob.uuid().utf8().data()));
 }
 
 }  // namespace
 
 namespace extensions {
 
 BlobNativeHandler::BlobNativeHandler(ScriptContext* context)
     : ObjectBackedNativeHandler(context) {
   RouteFunction("GetBlobUuid", base::Bind(&GetBlobUuid));
   RouteFunction("TakeBrowserProcessBlob",
                 base::Bind(&BlobNativeHandler::TakeBrowserProcessBlob,
                            base::Unretained(this)));
 }
 
 // Take ownership of a Blob created on the browser process. Expects the Blob's
 // UUID, type, and size as arguments. Returns the Blob we just took to
 // Javascript. The Blob reference in the browser process is dropped through
 // a separate flow to avoid leaking Blobs if the script context is destroyed.
 void BlobNativeHandler::TakeBrowserProcessBlob(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
-  DCHECK_EQ(3, args.Length());
-  DCHECK(args[0]->IsString());
-  DCHECK(args[1]->IsString());
-  DCHECK(args[2]->IsInt32());
+  CHECK_EQ(3, args.Length());
+  CHECK(args[0]->IsString());
+  CHECK(args[1]->IsString());
+  CHECK(args[2]->IsInt32());
   std::string uuid(*v8::String::Utf8Value(args[0]));
   std::string type(*v8::String::Utf8Value(args[1]));
   blink::WebBlob blob =
       blink::WebBlob::createFromUUID(blink::WebString::fromUTF8(uuid),
                                      blink::WebString::fromUTF8(type),
                                      args[2]->Int32Value());
   args.GetReturnValue().Set(blob.toV8Value(
       context()->v8_context()->Global(), args.GetIsolate()));
 }
 
 }  // namespace extensions