Revert of Fix scrollbar painting issue when scaling (patchset #5 id:80001 of https...

Revert of Fix scrollbar painting issue when scaling (patchset #5 id:80001 of https://codereview.chromium.org/841933002/)

Reason for revert:
This is causing test failures on memory bots, for some reason. For example:

http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20ChromeOS%20MSan%20Tests/builds/13

Example log output:
[ RUN      ] NineImagePainterTest.PaintScale
../../ui/gfx/nine_image_painter_unittest.cc:63: Failure
Value of: result.getColor(x, y)
  Actual: 4278255360
Expected: 0xFFFF0000
Which is: 4294901760
../../ui/gfx/nine_image_painter_unittest.cc:63: Failure
Value of: result.getColor(x, y)
  Actual: 4278255360
Expected: 0xFFFF0000
Which is: 4294901760
<snip, it goes on for a bit>

It is failing on a range of bots, including the above, but also:
http://build.chromium.org/p/chromium.memory.fyi/builders/Windows%20Unit%20%28DrMemory%29/builds/6
http://build.chromium.org/p/chromium.memory/builders/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/builds/11

Original issue's description:
> Fix scrollbar painting issue when scaling
>
> Calculation of dest width and height for nine image is not correct. We
> should use scale factor in transform matrix from canvas to calculate
> dest width/height, while use image_scale_ factor in canvas to calculate
> src width/height.
>
> BUG=447102
>
> Committed: https://crrev.com/aaa36193441db0782d5a425ac81931d03adafe7f
> Cr-Commit-Position: refs/heads/master@{#321061}

TBR=ananta@chromium.org,sky@chromium.org,reed@chromium.org,reed@google.com,qiankun.miao@intel.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=447102

Review URL: https://codereview.chromium.org/1006423009

Cr-Commit-Position: refs/heads/master@{#321084}