Revert 157422 "Remove lots of code related synchronously attaching"

Causing ASSERT failures in debug.

> Remove lots of code related synchronously attaching
> 
> Now that we always lazy attach we can remove the hacks and special
> cases related to synchronously attaching.
> 
> BUG=276689
> 
> Review URL: https://chromiumcodereview.appspot.com/23606020
> 
> git-svn-id: svn://svn.chromium.org/blink/trunk@157422 bbb929c8-8fbe-4397-9dbb-9b2b20218538

TBR=esprehn@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23526031

git-svn-id: svn://svn.chromium.org/blink/trunk@157431 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Gardening: fast/events/touch/gesture/pad-gesture-fling.html is still flaky on Windows 7 Release.

BUG=261277
TBR=bokan@chromium.org

Review URL: https://codereview.chromium.org/24064003

git-svn-id: svn://svn.chromium.org/blink/trunk@157432 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Assert that loading is complete in SVGImage::hasSingleSecurityOrigin()

This patch adds an assert that the "inner page" in an SVGImage has
loaded and does not have any pending subresource loads.

NOTRY=true
BUG=249037

Review URL: https://chromiumcodereview.appspot.com/22999031

git-svn-id: svn://svn.chromium.org/blink/trunk@157433 bbb929c8-8fbe-4397-9dbb-9b2b20218538