Make sure string passed to sendMessageToEmbedder is a valid unicode string

Source/core/inspector/InspectorFrontendHost.cpp

 /*
  * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Matt Lilek <webkit@mattlilek.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 142 matching lines @@
 void InspectorFrontendHost::setInjectedScriptForOrigin(const String& origin, const String& script)
 {
     m_frontendPage->inspectorController().setInjectedScriptForOrigin(origin, script);
 }
 
 void InspectorFrontendHost::copyText(const String& text)
 {
     Pasteboard::generalPasteboard()->writePlainText(text, Pasteboard::CannotSmartReplace);
 }
 
+static String escapeUnicodeNonCharacters(const String& str)
+{
+    StringBuilder dst;
+    for (unsigned i = 0; i < str.length(); ++i) {
+        UChar c = str[i];
+        if (c > 126) {

[alph, 2014/03/05 09:01:54]

126 seems to be too conservative. I'd suggest escaping only values larger than
the first surrogate value 0xD800.

[yurys, 2014/03/05 11:33:37]

PTAL: https://codereview.chromium.org/180113008/

+            unsigned symbol = static_cast<unsigned>(c);
+            String symbolCode = String::format("\\u%04X", symbol);
+            dst.append(symbolCode);
+        } else {
+            dst.append(c);
+        }
+
+    }
+    return dst.toString();
+}
+
 void InspectorFrontendHost::sendMessageToBackend(const String& message)
 {
     if (m_client)
-        m_client->sendMessageToBackend(message);
+        m_client->sendMessageToBackend(escapeUnicodeNonCharacters(message));
 }
 
 void InspectorFrontendHost::sendMessageToEmbedder(const String& message)
 {
     if (m_client)
-        m_client->sendMessageToEmbedder(message);
+        m_client->sendMessageToEmbedder(escapeUnicodeNonCharacters(message));
 }
 
 void InspectorFrontendHost::showContextMenu(Event* event, const Vector<ContextMenuItem>& items)
 {
     if (!event)
         return;
 
     ASSERT(m_frontendPage);
     ScriptState* frontendScriptState = mainWorldScriptState(m_frontendPage->mainFrame());
     ScriptObject frontendApiObject;
@@ skipping 15 matching lines @@
 {
     return RenderTheme::theme().activeSelectionForegroundColor().serialized();
 }
 
 bool InspectorFrontendHost::isUnderTest()
 {
     return m_client && m_client->isUnderTest();
 }
 
 } // namespace WebCore