Chrome was assembled from 25 different code libraries from Google and third parties such as Mozilla's Netscape Portable Runtime, Network Security Services, NPAPI, Skia Graphics Engine, SQLite, and a number of other open-source projects.[37] The V8 JavaScript virtual machine was considered a sufficiently important project to be split off (as was Adobe/Mozilla's Tamarin) and handled by a separate team in Denmark coordinated by Lars Bak at Aarhus. According to Google, existing implementations were designed "for small programs, where the performance and interactivity of the system weren't that important", but web applications such as Gmail "are using the web browser to the fullest when it comes to DOM manipulations and JavaScript", and therefore would significantly benefit from a JavaScript engine that could work faster.
Chrome uses the Blink rendering engine to display web pages. Based on WebKit, Blink only uses WebKit's "WebCore" components while substituting all other components, such as its own multi-process architecture in place of WebKit's native implementation.
Chrome is internally tested with unit testing, "automated user interface testing of scripted user actions", fuzz testing, as well as WebKit's layout tests (99% of which Chrome is claimed to have passed), and against commonly accessed websites inside the Google index within 20–30 minutes.
Google created Gears for Chrome, which added features for web developers typically relating to the building of web applications, including offline support. Google phased out Gears as the same functionality became available in the HTML5 standards.
On January 11, 2011 the Chrome product manager, Mike Jazayeri, announced that Chrome would remove H.264 video codec support for its HTML5 player, citing the desire to bring Google Chrome more in line with the currently available open codecs available in the Chromium project, which Chrome is based on. Despite this, on November 6, 2012, Google released a version of Chrome on Windows which added hardware-accelerated H.264 video decoding. In October 2013, Cisco announced that it was open-sourcing its H.264 codecs and will cover all fees required.
On February 7, 2012, Google launched Google Chrome Beta for Android 4.0 devices. On many new devices with Android 4.1 and later preinstalled, Chrome is the default browser.
On April 3, 2013, Google announced that it would fork the WebCore component of WebKit to form its own layout engine known as Blink. The aim of Blink will be to give Chrome's developers more freedom in implementing its own changes to the engine, and to allow its codebase to be trimmed of code that is unnecessary or unimplemented by Chrome.
(Wikipedia)
