Nouvelle version 44.0 de Firefox

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

Windows XP and Vista screensaver doesn't disable when watching videos (Bug 1193610)
Various security fixes

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

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
Service Workers API
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