[Transparency] add javascript function and manifest, OSX Implementation, stubs for Linux/Windows
[Transparency][WIN/Linux] rebase for the new chrome (+1 squashed commits)

Squashed commits:

[393645c] [Transparency][Win] add d3dcompiler_46 when packaging, fix the marginVal for compatibility (+1 squashed commits)

Squashed commits:

[26d1c7e] [Transparency][WIN] implement the windowsversion, changing the style, and background
[Transparency] add switch to disable the code
Merge pull request #2463 from jtg-gg/transparency

#132 support for screen Transparency on WIN/OSX/Linux