Fix cluster-fuzz crash with internal EventSender API.

content/shell/renderer/test_runner/event_sender.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 "content/shell/renderer/test_runner/event_sender.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ skipping 1357 matching lines @@
       std::string function_key_name = base::StringPrintf("F%d", i);
       if (function_key_name == code_str) {
         code = ui::VKEY_F1 + (i - 1);
         domString = function_key_name;
         break;
       }
     }
     if (!code) {
       WebString web_code_str =
           WebString::fromUTF8(code_str.data(), code_str.size());
-      DCHECK_EQ(1u, web_code_str.length());
+      if (web_code_str.length() != 1u) {
+        v8::Isolate* isolate = blink::mainThreadIsolate();
+        isolate->ThrowException(v8::Exception::TypeError(
+            gin::StringToV8(isolate, "Invalid web code.")));
+        return;
+      }
       text = code = web_code_str.at(0);
       needs_shift_key_modifier = NeedsShiftModifier(code);
       if ((code & 0xFF) >= 'a' && (code & 0xFF) <= 'z')
         code -= 'a' - 'A';
       if ((code >= 'A' && code <= 'Z') || (code >= 'a' && code <= 'z')) {
         domString.assign("Key");
         domString.push_back(base::ToUpperASCII(code));
       } else if (code >= '0' && code <= '9') {
         domString.assign("Digit");
         domString.push_back(code);
@@ skipping 1123 matching lines @@
 
 bool EventSender::HandleInputEventOnViewOrPopup(const WebInputEvent& event) {
   if (WebPagePopup* popup = view_->pagePopup()) {
     if (!WebInputEvent::isKeyboardEventType(event.type))
       return popup->handleInputEvent(event);
   }
   return view_->handleInputEvent(event);
 }
 
 }  // namespace content