[DevTools] Replace usages of document with custom functions.

[DevTools] Replace usages of document with custom functions.

This patch replaces the following document.XXXX functions with window.XXXX custom ones:
- createDocumentFragment;
- createElement;
- createElementWithClass;
- createTextNode.

BUG=424188
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=183892

[dgozman, 2014-10-17 11:41:55]

dgozman@chromium.org changed reviewers:
+ apavlov@chromium.org, pfeldman@chromium.org

[dgozman, 2014-10-17 11:41:56]

Take a look please. The only interesting change is in DOMExtension.js.

[pfeldman, 2014-10-17 13:10:57]

lgtm

[dgozman, 2014-10-17 13:11:55]

The CQ bit was checked by dgozman@chromium.org

[commit-bot: I haz the power, 2014-10-17 13:13:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/662793002/1

[commit-bot: I haz the power, 2014-10-17 15:23:31]

Committed patchset #1 (id:1) as 183892