IndexedDB: compare strings without decoding

IndexedDB: compare strings without decoding
https://bugs.webkit.org/show_bug.cgi?id=68554

Patch by Joshua Bell <jsbell@chromium.org> on 2011-09-21
Reviewed by Tony Chang.

Resolves a FIXME in IndexedDB that was also identified as a hotspot
during profiling. Yields a small performance improvement.

* Source/WebCore/storage/IDBLevelDBCoding.cpp:
* Source/WebCore/storage/IDBLevelDBCoding.h:
* Source/WebKit/chromium/tests/IDBLevelDBCodingTest.cpp:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@95682 268f45cc-cd09-0410-ab3c-d52691b4dbfc