Google Chrome 21.0.1180.60

* Contains a number of new features including a new API for high-quality video and audio communication.
* Security fixes
- Missing re-prompt to user upon excessive downloads.
- Overly broad file access granted after drag+drop.
- Off-by-one read in GIF decoder.
- Various lower severity issues in the PDF viewer.
- Integer overflows in PDF viewer.
- Use-after-free with bad object linkage in PDF.
- webRequest can interfere with the Chrome Web Store.
- Leak of pointer values to WebUI renderers.
- Use-after-free in PDF viewer.
- Out-of-bounds writes in PDF viewer.
- Use-after-free in CSS DOM.
- Buffer overflow in WebP decoder.
- Out-of-bounds access when clicking in date picker.