Fixed a couple of failing DCHECK(has_pending_exception()).

src/debug.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 590 matching lines @@
   Handle<String> script_name =
       factory->NewStringFromAscii(name).ToHandleChecked();
   Handle<Context> context = isolate->native_context();
 
   // Compile the script.
   Handle<SharedFunctionInfo> function_info;
   function_info = Compiler::CompileScript(
       source_code, script_name, 0, 0, ScriptOriginOptions(), Handle<Object>(),
       context, NULL, NULL, ScriptCompiler::kNoCompileOptions, NATIVES_CODE,
       false);
-
-  // Silently ignore stack overflows during compilation.
-  if (function_info.is_null()) {
-    DCHECK(isolate->has_pending_exception());
-    isolate->clear_pending_exception();
-    return false;
-  }
+  if (function_info.is_null()) return false;
 
   // Execute the shared function in the debugger context.
   Handle<JSFunction> function =
       factory->NewFunctionFromSharedFunctionInfo(function_info, context);
 
   MaybeHandle<Object> maybe_exception;
   MaybeHandle<Object> result = Execution::TryCall(
       function, handle(context->global_proxy()), 0, NULL, &maybe_exception);
 
   // Check for caught exceptions.
@@ skipping 2734 matching lines @@
   logger_->DebugEvent("Put", message.text());
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 } }  // namespace v8::internal