The focus on this release has been feature polish, stability improvement, and extensions work.

Extensions:
Lots of work to polish and stabilize the browser and page action APIs:
* [r29556] Add badge text color API. Also change color APIs from ARGB to RGBA (breaking change, sorry!) (Issues: 24635, 24644, 25215)
* [r29152, r29785] Browser actions (buttons, popups) are now implemented. (Issue: 23882, 23897)
* [r29997] Add support for tab-specific state to browser actions. Also, fix the bug where only the first call to setIcon() works. (Issues: 24669,24472)
* [r30346] Constrain browser action popups to a min/max size. Also fix some glitches in popup sizing. (Issue 25214)
* [r30499] Use a better signature for the new page actions API (chrome.pageAction.* instead of chrome.pageActions.*). This is technically a breaking change, but hopefully not too many people had gotten around to using the new API yet. (Issue 25833)
* [r29665] Remove toolstrips on linux. They were causing lots of crashes and are going away soon anyway. (Issue 25106)
* [r29911] Add chrome.extension.sendRequest() -- a simpler way to do content script messaging. (Issue 23865)
* [r30341] Add new event chrome.tabs.onStatusChange. This makes the common case of wanting to know when tabs load much easier. (Issue 21729)

Other miscellaneous cleanup:
* [r29498] Correctly handle reloading in the task manager (Issue 18693)
* [r29555] Fix bug where content scripts did not always apply to first page load (Issue 11547)
* [r29714, r29922, r29935, r30219] Various cleanup for the extension management page (Issues 12119, 25509, 25471)
* [r30091] Improve install UI on mac (Issue 19654)
* [r30312] Filter out hidden files when loading and packing extensions (Issue 23004)
* [r30326] Copy chrome.extension.getTabContentses() to chrome.extension.getExtensionTabs(). Nobody liked the old name. (Issue 21433)
* [r30384] Use the puzzle piece as the default extension icon. (Issue 25906)
* [r30481] Hide the theme install bubble a little earlier. It was overlapping with the install dialog on linux. (Issue 26130)