Supported Projects

The //net stack is used on a variety of platforms and in a variety of open source projects. These different platforms and projects have differing degrees of support from //net OWNERS as well as differing requirements for designs and technical requirements.

Note that this is a rough high-level overview of the major projects; as more of //net is broken into consumable services/components as part of the Mojo servicificaiton efforts, it's likely that there will be a larger number of ‘variants’ of these projects with different constraints and features.

Google Chrome Browser

The Google Chrome browser, which lives in //chrome, is the most important //net consumer and shapes many of the core design decisions. In general, features that are not intended with or not compatible with the needs of the Google Chrome browser will have a very high bar for acceptance in //net.

The feature matrix

• Supported Platforms: Windows, macOS, Linux, Chromium OS, iOS, Android
• Release Frequency: ~6 weeks between releases
• Automatic Updates: Yes
• Command-line Flags:
  • Yes: Windows, macOS, Linux, Chromium OS (Dev image), Android (rooted)
  • No: Chromium OS (Release image), iOS, Android (Release)
• Field Trials (Finch): Yes
• Enterprise Policy: Yes
• User Metrics (UMA): Yes
• Component Updater: Yes

Chromium Browser

The Chromium browser refers to the practice of certain Linux distributions to bundle the open-source components of Chrome Browser in //chrome, branded as Chromium. This version is not distributed by Google, but by individual Linux distributions (primarily). Other distributions based on building Chromium for other platforms exist, although do not see as wide of usage.

• Supported Platforms: Windows, macOS, Linux, Chromium OS, iOS, Android
• Release Frequency: Varies by distributor; some Linux distributions treat versions of Chromium as “Long Term Stable” and support a single version for a longer time than the Chromium projects do, others track the Google Chrome release frequency.
• Automatic Updates: Varies by distributor
• Command-line Flags:
  • Yes: Windows, macOS, Linux, Chromium OS (dev image), Android (rooted)
  • No: Chromium OS (Release image), iOS, Android (Release)
• Field Trials (Finch): No
• Enterprise Policy: Yes
• User Metrics (UMA): Varies by distributor
• Component Updater: Varies by distributor

Android WebView

Distinct from the Chromium browser, the Android WebView is itself based on the Chromium browser. On official Android devices running Android N or later, WebView is automatically updated when Google Chrome is updated on the device. For earlier devices, Android WebView is updated by the System WebView component.

Android WebView may also be used on non-official Android devices, such as those based on the Android Open Source Project but do not go through the Android Compatability Test Suite. Such releases have limited to no interaction with the Chromium projects, and so their capabilities cannot be conclusively documented.

For official Android devices, WebView has the following capabilities.

• Supported Platforms: Android
• Release Frequency: ~6 weeks between releases
• Automatic Updates: Varies. Updates are made available on the Android App Store, but users must explicitly choose to update. As such, the rate of update varies much more than for the Chromium browser.
• Command-line Flags: No for production devices, yes for userdebug devices
• Field Trials (Finch): Yes, with caveats
• Enterprise Policy: Yes, with caveats (TODO(rsleevi): document caveats)
• User Metrics (UMA): Yes, with caveats
• Component Updater: No

//content Embedders

In addition to Chromium, there are a number of other of embedders of //content, such as projects like Chromium Embedded Framework or Electron. While //net does not directly support these consumers, it does support the //content embedding API that these projects use. Note that this excludes the content_shell test framework.

• Supported Platforms: Windows, macOS, Linux, Chromium OS, iOS, Android
• Release Frequency: Varies by consumer; Officially ~6 weeks
• Command-line Flags: Varies by consumer
• Field Trials (Finch): No
• Enterprise Policy: No
• User Metrics (UMA): No
• Component Updater: No

Cronet

Cronet is a version of the //net network stack for use in mobile applications on iOS and Android. While primarily targetting first-party Google applications, Cronet's status as an open-source project, similar to the Chromium browser, means that it may find itself embedded in a variety of other projects.

Unlike some of the other //net consumers, Cronet does not necessarily implement “The Web Platform” (as the holistic set of user agent-focused features), and instead is more akin to an HTTP(s) client networking library.

• Supported Platforms: iOS, Android
• Release Frequency: Varies. While “releases” are made following the same frequency as Google Chrome, because it is treated similar to a “third-party” library, different products and projects will ship different versions of Cronet for differing periods of time.
• Command-line Flags: No
• Field Trials (Finch): No
• Enterprise Policy: No
• User Metrics (UMA):
  • Yes: First-party (Google) projects, although they will be reported in project-specific buckets (e.g. no overarching set of metrics for all Cronet consumers).
  • No: In general
• Component Updater: No