refactor($emplateRequest): simplify filtering out of transform functions

[pkozlowski-opensource]

I guess it might be just me but I find it a lot easier to read / understand this chunk of code when it is written using the .filter method.

Unless the code was written like this for perf reasons.

[googlebot]

CLAs look good, thanks!

[pkozlowski-opensource]

Oh, it looks like I wasn't the only thinking about this change, see https://github.com/shahata/angular.js/commit/58042eefce097a4cd478e433116b39f9354a314d in #9745

[shahata]

I guess the original reason for this was that IE8 didn't support it. Thankfully we don't need to worry about that anymore.

[pkozlowski-opensource]

Not sure IE8 was the reason as it was introduced only in 1.3. Here is the initial commit: a70e283

I guess @caitp knows more - was the current code perf-motivated?

[caitp]

I thought we already merged @shahatas refactoring

[pkozlowski-opensource]

no, we didn't as it was part of more changes in #9745 (this is why it is always good idea to send small, focused PRs :-))