Don't throw exceptions when v8 objects/contexts are missing, and catch

chrome/renderer/extensions/miscellaneous_bindings.cc

 // Copyright (c) 2012 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 "chrome/renderer/extensions/miscellaneous_bindings.h"
 
 #include <map>
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 146 matching lines @@
     extensions::ScopedPersistent<v8::Function> callback;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(GCCallbackArgs);
   };
 
   static void GCCallback(v8::Isolate* isolate,
                          v8::Persistent<v8::Value> object,
                          void* parameter) {
     v8::HandleScope handle_scope;
-    GCCallbackArgs* args = reinterpret_cast<GCCallbackArgs*>(parameter);
+    GCCallbackArgs* args = static_cast<GCCallbackArgs*>(parameter);
     WebKit::WebScopedMicrotaskSuppression suppression;
-    args->callback->Call(args->callback->CreationContext()->Global(), 0, NULL);
+    // Wrap in try/catch here so that we don't call into any message/exception
+    // handlers during GC. That is a recipe for pain.
+    v8::TryCatch trycatch;
+    args->callback->Call(v8::Object::New(), 0, NULL);
     delete args;
   }
 
   // Binds a callback to be invoked when the given object is garbage collected.
   v8::Handle<v8::Value> BindToGC(const v8::Arguments& args) {
-    if (args.Length() == 2 && args[0]->IsObject() && args[1]->IsFunction()) {
-      GCCallbackArgs* context = new GCCallbackArgs(
-          v8::Handle<v8::Object>::Cast(args[0]),
-          v8::Handle<v8::Function>::Cast(args[1]));
-      context->object.MakeWeak(context, GCCallback);
-    } else {
-      NOTREACHED();
-    }
+    CHECK(args.Length() == 2 && args[0]->IsObject() && args[1]->IsFunction());
+    GCCallbackArgs* context = new GCCallbackArgs(
+        v8::Handle<v8::Object>::Cast(args[0]),
+        v8::Handle<v8::Function>::Cast(args[1]));
+    context->object.MakeWeak(context, GCCallback);
     return v8::Undefined();
   }
 };
 
 }  // namespace
 
 namespace extensions {
 
 ChromeV8Extension* MiscellaneousBindings::Get(
     Dispatcher* dispatcher,
@@ skipping 129 matching lines @@
     } else {
       arguments.push_back(v8::Null());
     }
     (*it)->CallChromeHiddenMethod("Port.dispatchOnDisconnect",
                                   arguments.size(), &arguments[0],
                                   NULL);
   }
 }
 
 }  // namespace extensions