On Chrome OS, users should be able to work with files in the cloud as easily as they work with local files.
Today, users often have their files spread all over the cloud -- with documents in one place, their photos in another, and videos somewhere else. Working across all of those systems can be a challenge, which is where the File System Provider API in Chrome OS can help. With the File System Provider API, users who install your Chrome App can have your Cloud service seamlessly integrated into the Chrome OS Files app. Working with multiple storage backends becomes as easy as dragging and dropping files locally.

As usual, users can install your Chrome app or extension from the Chrome Web Store. Or, they can add new services directly from the Files app. The new file system will then appear directly in the left navigation column. Users can browse this file system anywhere the Files app is shown, including Save as and Open dialogs.

Screenshot 2015-04-29 at 12.36.48 PM.png

Your extension just needs to call chrome.fileSystemProvider.mount and respond to the listed events. Developers have already created some great apps, including the official client, an SMB client, and even a way to browse TED talks locally. Check out the documentation or join the mailing list to stay informed about announcements and API changes.

Posted by Tomasz Mikolajewski, Filesystem Fiend

The newest Chrome Beta channel release includes new ES6 features and a number of updates to existing APIs. Unless otherwise noted, changes described below apply to Chrome for Android, Windows, Mac, Linux and Chrome OS.

Improved notification capabilities

Chrome 42 allowed users to opt in to receive push notifications from sites even after the page is closed. Sites may now use getNotifications to observe which of their notifications are still being displayed, and to store a payload with a notification so they can determine which notification was clicked.

Promoted add to homescreen improvements

Since Chrome 42, users who frequently visited a high-quality web app on Android saw a banner allowing them to add the site to their home screen in one tap. In this release Chrome fires a cancellable beforeinstallprompt event before the banner is shown, allowing developers to measure user interaction with the feature. Developers are also now able to offer the banner for their native Android app.

ES6 computed property names

Until now, developers defining a JavaScript object literal needed to know the names of all of its properties before runtime. This release increase the expressiveness of the object literal syntax by providing support for ES6 computed property names, allowing developers to put an expression in brackets [], to be computed as the property name at runtime.

let propertyName = "foo";
let obj = {
 [propertyName + "IsTrue"]: true,
 contains: 12

Other updates in this release
  • Chrome’s implementation of the Push API has undergone several minor breaking changes in order to keep up to date with the evolving specification.
  • ES6 extended Unicode escape sequences allow developers to use the extended set of Unicode characters in JavaScript string literals, where previously characters whose escape sequences contain more than four hexadecimal values were unable to be denoted.
  • This release includes a new implementation of multi-column layout by Opera engineer Morten Stenshorne, solving historic issues with incorrect column balancing.
  • Developers should now use the scroll attributes of document.scrollingElement instead of document.body as the latter has several well known issues.

As always, visit for a complete overview of Chrome’s developer features, and circle +Google Chrome Developers for more frequent updates.

Posted by Peter Beverloo, Software Engineer and Notification Newsmaker

We talked about the power of the mobile web during the Google I/O keynote yesterday. The mobile web reaches far and wide and is great at connecting users with content, since it’s so easy to go from one page to the next. In fact, the average Chrome for Android user navigates to more than 100 domains per month.

The mobile web is an excellent way to build a successful business, and we want to help you do it in three ways; develop your content, engage new users, and monetize your work. 

Mobile web development can be complicated, but we don’t think it should be. Yesterday, we announced Polymer 1.0, a new way to build web applications. In addition to this first production-ready release for the web components library, we released brand-new sets of elements built with Polymer that range from toolbars and menus to offline caching and mobile-first checkout flows. When you visit Polymer’s new element catalog, you can check out documentation, play with demos, and download elements. And if you're new to the platform, you can check out our starter kit. Packed with the latest features, the starter kit works out of the box so you can focus on adding features right away.

Having many users discover your site is great, but you also want them to be able to build a meaningful relationship with it. We're bringing some of the most compelling capabilities from native apps to sites in a way that maintains what's great about the web with push notifications and add-to-homescreen buttons. This allows your users to interact more deeply with your content.

Push Notifications

Purchases today involve a checkout form, and forms can be the deciding factor for whether someone makes a purchase on your site. Autofill helps users complete forms up to 30% faster, so we’re expanding our support with credit cards and addresses from Google Payments. This means that the same information that’s used to make purchases inside the Google Play store can now be applied to websites. By using the standard autocomplete attributes, you can make the checkout process easier by having Chrome autofill your forms with 100% accuracy. Just tell us what the field is and we'll fill it in -- no guessing.

What’s Next
One of our next big hurdles is improving the transition between mobile apps and the mobile web. 
Native app developers often face a tough choice when a user taps a URL in their app: they can send users to a browser - interrupting the user experience, or they can build their own in-app browser with WebViews - resulting in a lot of work for only a basic browsing experience. 
We talked about Pinterest being an early adopter during our keynote; another good example is an app like Twitter that helps users find and share great web content. Users frequently move between native and web content in the app, so giving them a seamless experience is key. Users also want to easily take actions specific to Twitter, like retweeting or sending links in direct messages, which aren’t options in a typical browser.

In this week's Chrome dev channel we're introducing Chrome custom tabs, a new way for native apps to control their web experience without having to resort to a webview. You can change color schemes, animations, and add custom actions to the toolbar, while giving users a full browsing experience with their cookies, saved passwords, and features like Data Saver and Google Translate.

Chrome is committed to making sure that you can develop easily, engage with your users, and build a thriving business around the web. For the latest news and upcoming developer events, subscribe to this blog and follow us on Twitter@ChromiumDev.

Posted by Rahul Roy-chowdhury, Chief Web Fanboy and Product Manager

We’re always working to improve Chrome extensions while keeping our users as safe as possible. In May 2014 we announced a new policy to protect Windows users by enforcing that extensions be hosted on the Chrome Web Store. The results were encouraging: we saw a 75% drop in customer support help requests for uninstalling unwanted extensions. Consequently, we will expand the reach of this protection to all Windows and Mac users in the coming months.

We originally did not enforce this policy on the Windows developer channel in order to allow developers to opt out. Unfortunately, we’ve since observed malicious software forcing users into the developer channel in order to install unwanted off-store extensions. Affected users are left with malicious extensions running on a Chrome channel they did not choose. As such, starting today we will begin enforcing this policy on all Windows channels. Mac will soon follow, with enforcement for all channels beginning in July 2015.

For developers, we’ll continue to support local extension installs during development as well as installs via Enterprise policy. To provide an integrated install flow from your own website, you can make use of the existing inline installation feature. If you run into problems or think an extension was disabled incorrectly, please reach out to us in our support forums. If you’ve developed an extension not yet in the Chrome Web Store, we encourage you to submit it today.

The extension platform unlocks powerful features that can help users get the most out of Chrome. However, it is crucial that our users stay safe from the reaches of malicious software developers. Extending this protection is one more step to ensure that users of Chrome can enjoy all the web has to offer without the need to worry as they browse.

Posted by Jake Leichtling,  Extensions Platform Product Manager

Earlier this month, Chrome began utilizing new techniques to get pages in front of users faster. That's an important piece of the performance story, but it's just one - what about once the page has loaded fully? That's when users want pages to animate smoothly and react quickly to their scrolls and clicks. Chrome 41 included a task scheduler for Chrome's rendering engine that ensures those high-priority tasks are handled immediately, making Chrome feel snappier and run closer to a smooth 60 frames per second.

Given that ambitious goal, Chrome has just milliseconds to produce every frame. But painting graphics to the screen isn't all that Chrome does, and there can be several different tasks contending for a single processor core. Historically Chrome handled execution of tasks, such as animating an image, responding to a click, or doing some memory operations, the same way that a bank handles a queue of customers: the first one line in is the first one handled. While this is simple and straightforward, it's not always the best for optimal performance. An urgent task, such as painting the next frame to the screen, might be added to the end of a long queue of pending tasks. The 60 frames per second goal would be lost.
Starting in Chrome 41, we've created a task scheduler integrated into the Blink rendering engine. The scheduler is capable of evaluating pending tasks and reordering them so that the most urgent tasks, such as animating and responding to a user's action, are prioritized ahead of others. Lower priority tasks, such as clearing out unused memory, are delayed until the processor has available time. In practice, this results in up to a 40% higher responsiveness to user input when Chrome is working hard to draw frames.
However, even the most advanced scheduler can't properly queue up tasks without knowing what's coming in the future. To address this, the Blink scheduler is also integrated with Chrome's graphics engine, which has precise knowledge of when Chrome will need to deprioritize other tasks in order to paint graphics to the screen. This allows the scheduler to consider lower priority tasks and schedule only those tasks that fit nicely into the otherwise "idle" time before Chrome needs to draw another frame. These tasks are handled essentially for free, with no impact on the smooth, 60 frames-per-second animations.

The latest version of Chrome scrolling a particularly challenging website, with the scheduler enabled (left) and disabled (right).

These changes demonstrate that performance isn't just about doing things faster - it's also about doing things smarter, in the right order, and at the right time. Stay tuned for more updates about how we're using Chrome's scheduler to push the bounds of performance.

Posted by Sami Kyostila and Ross McIlroy, Senior Task Masters

Chrome's Dev channel allows you to test out your sites using an early version of Chrome to find bugs and try out cutting edge features before they're released to everyone. Historically the Dev channel was available for Windows, Mac, Linux, and ChromeOS, and starting today, the Dev channel is available for Android as well.

Just like the Dev channel on other platforms, it will be updated at least every week, and your feedback will help directly help us avoid regressions and improve features for Beta and Stable users. Life on the Dev channel can be rocky at times, so on Android it installs side-by-side with any other versions of Chrome you have on your device.

We hope you find this additional channel to be a useful early look into what’s coming for Chrome on Android.

Posted by Jason Kersey, Chrome Technical Program Manager and Update Button-pusher

One of the web’s superpowers is its low friction: a new site is always only a single tap away, allowing users to easily navigate through a rich diversity of experiences. The mobile web provides a great discovery experience for users and unparalleled reach for developers.

Unfortunately, once users discover an experience they love, it is hard for them to build a meaningful relationship since websites lack the engaging capabilities developers have come to expect from mobile such as push notifications and home screen icons. As a result, developers have needed to decide between the engagement potential of a native app and the reach potential of a mobile website.

Chrome 42 addresses this dilemma by allowing users to engage more deeply with the mobile web experiences that are important to them, by both opting in to receive push notifications directly from websites and easily adding regularly-visited high-quality sites to their home screen.

Push Notifications
Timely, personalized notifications save users the effort of manually checking for updates throughout the day and have enabled a host of new experiences from real time communication to live updates on breaking news.

This release of Chrome supports the new emerging web standard for push notifications on Android and desktop, enabling users to opt in to allow a specific website to send them push notifications just like an installed native app. Over the coming weeks, mobile web users will be able to opt in to receiving push notifications from early adopters including Beyond the Rack, eBay, Facebook, FanSided, Pinterest, Product Hunt, and VICE News. Roost and Mobify also provide services that make it easy for developers to integrate web-based push notifications into their site with minimal custom implementation work.
Promoting Add to Home Screen
Mobile users often open their phones to pass time while on the bus or waiting in line. Home screen icons help them easily jump back into their favorite experiences with just a single tap. In this release of Chrome for Android, users who frequently visit a modern, mobile-optimized website such as Flipboard or Medium will be offered the option to easily add the site directly to their home screen in one tap, allowing them to keep in touch and engaged throughout the day.
Developers can now take advantage of these and other recent changes including improved performance, full offline support, and access to device capabilities such as the camera and geolocation to deliver more meaningful experiences on the web than ever before. These new features will continue to improve and evolve over time, diminishing the difficult choice for developers between the reach of the mobile web and the engagement of native apps.

Posted by Miguel Garcia, Push Maestro and Owen Campbell-Moore, Engagement Optimizer