Google announced Octane: the JavaScript benchmark suite for the modern web

Google released Octane, a JavaScript benchmark suite that aims to measure a browser’s performance when running the complex and demanding web applications that users interact with daily.

overview of the new tests:

• Box2DWeb runs a JavaScript port of a popular 2D physics engine that is behind many well-known simulations and web games.
• Mandreel puts a JavaScript port of the 3D Bullet Engine to the test with a twist: The original C++ source code for the engine is translated to JavaScript by Onan Games’ Mandreel compiler, which is also used in countless web-based games.
• Pdf.js is based on Mozilla’s PDF reader and shows how Javascript applications can replace complex native browser plug-ins. It measures how fast the browser decodes a sample PDF document.
• GB Emulator is derived from an open source emulator of a famous game console running a 3D demo.
• CodeLoad measures how quickly a JavaScript engine can bootstrap commonly used JavaScript libraries and start executing code in them. The source for this test is derived from open source libraries (Closure, jQuery).

Source: Chromium Blog - Octane: the JavaScript benchmark suite for the modern web