Firefox 44 发布，更新如下：
New
Improved warning pages for certificate errors and untrusted connections
Enable H.264 if system decoder is available
Enable WebM/VP9 video support on systems that don't support MP4/H.264
In the animation-inspector timeline, lightning bolt icon next to animations running on the compositor thread
Support the brotli compression format via HTTPS content-encoding
Screenshot commands allow user choice of pixel ratio in Developer Tools
Fixed
Windows XP and Vista screensaver doesn't disable when watching videos (Bug 1193610)
Various security fixes
Changed
To support unicode-range descriptor for webfonts, font matching under Linux now uses the same font matching code as other platforms
Use a SHA-256 signing certificate for Windows builds, to meet new signing requirements
Firefox has removed support for the RC4 decipher
Firefox will no longer trust the Equifax Secure Certificate Authority 1024-bit root certificate or the UTN - DATACorp SGC to validate secure website certificates
Stricter validation of web fonts
On-screen keyboard support temporarily turned off for Windows 8 and Windows 8.1
Developer
Right click on a logged object in the console to store it as a global variable on the page
Visual tools for Animation:
View/Edit CSS animation keyframe rules directly in the inspector
Visually modify the cubic-bezier curve that drives the way animations progress through time
Discover and scrub through all CSS animations and transitions playing on the page
Learn more: http://devtoolschallenger.com/
Visual tools for Layout and Styles:
Display rulers along the viewport to verify size and position and use the measurement tool to easily detect spacing and alignment problems
Use CSS filters to preview and create real-time effects like drop-shadows, sepia, etc
Learn more: http://devtoolschallenger.com/
New memory tool for inspecting the memory heap
Built-in JSON reader to intuitively view, search, copy and save data without extensions
Jump to function definitions in the debugger with Cmd-Click
WebSocket Debugging API and add-on
The rule view now displays styles using their authored text, and edits in the rule view are now linked to the style editor
详情请看：release notes