Clean up transform methods in GraphicsContext.

Clean up transform methods in GraphicsContext.

GraphicsContext::scale takes a FloatSize, which is not the way most
callers wish to invoke it. Here we change it to take x and y scale.

GraphicsContext::getCTM is not truly reflective of the tranforms
applied to get a pixel on the screen, as it ignores compositor applied
transforms. There are numerous locations where the CTM is used to test
pixel-level results, such as the width of a line. These tests are not
accurate in the presence of high DPI or other zoom factors. Each
location gets a FIXME indicating the problem.

R=fmalita,esprehn
BUG=383070, 382491
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=175960

[Stephen Chennney, 2014-06-10 20:38:11]

Simple cleanup and placeholder for future fixes.

Web code should be rubber stamp.

[esprehn, 2014-06-11 00:08:04]

lgtm

[commit-bot: I haz the power, 2014-06-11 00:09:01]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/schenney@chromium.org/323013004/40001

[commit-bot: I haz the power, 2014-06-11 01:07:53]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu_trigger...)
  win_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu_triggered...)

[commit-bot: I haz the power, 2014-06-11 01:08:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-06-11 01:08:04]

Try jobs failed on following builders:
  linux_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu_trigger...)
  win_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu_triggered...)

[Stephen Chennney, 2014-06-11 15:26:46]

The CQ bit was checked by schenney@chromium.org

[commit-bot: I haz the power, 2014-06-11 15:27:08]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/schenney@chromium.org/323013004/40001

[commit-bot: I haz the power, 2014-06-11 15:28:26]

Change committed as 175960