Merge 153283 - Make ModuleSystem::DumpException() handle empty handles.

chrome/renderer/module_system.cc

Index: chrome/renderer/module_system.cc
===================================================================
--- chrome/renderer/module_system.cc	(revision 153758)
+++ chrome/renderer/module_system.cc	(working copy)
@@ -67,12 +67,23 @@
     return;
   }
 
-  LOG(ERROR) << "["
-             << *v8::String::Utf8Value(
-                 message->GetScriptResourceName()->ToString())
-             << "(" << message->GetLineNumber() << ")] "
-             << *v8::String::Utf8Value(message->Get())
-             << "{" << *v8::String::Utf8Value(try_catch.StackTrace()) << "}";
+  std::string resource_name = "<unknown resource>";
+  if (!message->GetScriptResourceName().IsEmpty()) {
+    resource_name = *v8::String::Utf8Value(
+                 message->GetScriptResourceName()->ToString());
+  }
+
+  std::string error_message = "<no error message>";
+  if (!message->Get().IsEmpty())
+    error_message = *v8::String::Utf8Value(message->Get());
+
+  std::string stack_trace = "<stack trace unavailable>";
+  if (!try_catch.StackTrace().IsEmpty())
+    stack_trace = *v8::String::Utf8Value(try_catch.StackTrace());
+
+  LOG(ERROR) << "[" << resource_name << "(" << message->GetLineNumber() << ")] "
+             << error_message
+             << "{" << stack_trace << "}";
 }
 
 void ModuleSystem::Require(const std::string& module_name) {