Revert "Enforce clearing renderers' paint invalidation state"

Reason: The following Linux Chrome OS browsertests hit the assert:
GalleryBrowserTest.CropImageOnDrive
GalleryBrowserTest.DeleteImageOnDownloads
GalleryBrowserTest.RenameImageOnDrive
GalleryBrowserTest.RotateImageOnDownloads
GalleryBrowserTestInGuestMode.ExposureImageOnDownloads

Link: http://build.chromium.org/p/chromium.webkit/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%281%29/builds/248

Excerpt from log:
SHOULD NEVER BE REACHED
../../third_party/WebKit/Source/core/rendering/RenderObject.h(253) : void WebCore::RenderObject::assertRendererClearedPaintInvalidationState() const

This reverts r178089 (real patch), r178102 (adds autobaseline), r178119 (ARB 1), r178114 (ARB 2)

BUG=385169
TBR=jchaffraix
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/393673003

git-svn-id: svn://svn.chromium.org/blink/trunk@178120 bbb929c8-8fbe-4397-9dbb-9b2b20218538