This establishes a single naming for all our blobs with browser
builds that we upload to CDN: `<browser-name>-<os-version>`
- `<browser-name>` is either `firefox` or `webkit`.
- `os-version` is the OS that was used to produce the build.
References #2745
This patch establishes the following convention:
- scripts `checkout_build_archive_upload.sh` and `upload.sh` now accept
build flavor instead of browser name. Build flavor fully defines the
build produced / uploaded.
- scripts under `//browser_patches/webkit` and
`//browser_patches/firefox` produce build that is specific to the host
system.