Get Win32K lockdown for renderers working again on Windows 8+.

Get Win32K lockdown for renderers working again on Windows 8+.

This regressed recently with the change to query the device scale factor to see if it needs to be scaled back to 1.0 for
display scales equal to or under 125%. user32/gdi32 API's crash or fail with the Win32K lockdown process mitigation.

Fix is to ensure that the device scale factor is queried from the one set via the command line. The other change is to move
the code in ContentMainRunner::Initialize which sets the global device scale factor for the process to before the content client
initialization. This is because the ShellContentRendererClient in its ctor calls the ShouldUseDirectWrite function which relies on
the GetDPIScale function to decide whether or not directwrite should be enabled. This causes a DCHECK in content_browsertests.

To ensure that the win32k lockdown does not regress I added a simple content browsertest RendererWin32KLockdownNavigationTest which runs
this on Windows 8+.

The accessibility fixes are to get the browser tests to run
on Windows 8. There were special cases to always enable
accessibility on Windows 8 for historical reasons. These are
no longer necessary as we don't rely on accessibility to display the virtual keyboard.

BUG=417147
Committed: https://crrev.com/b1f9313020d4c1e8619f21b5320a0255bf313b4b
Cr-Commit-Position: refs/heads/master@{#296859}

[ananta, 2014-09-24 23:49:26]

ananta@chromium.org changed reviewers:
+ jam@chromium.org, scottmg@chromium.org, sky@chromium.org

[ananta, 2014-09-24 23:49:27]

sky for ui
jam for content
scottmg for everything.

[sky, 2014-09-24 23:51:15]

https://codereview.chromium.org/600263002/diff/1/ui/gfx/win/dpi.cc
File ui/gfx/win/dpi.cc (right):

https://codereview.chromium.org/600263002/diff/1/ui/gfx/win/dpi.cc#newcode137
ui/gfx/win/dpi.cc:137: float dpi_scale =
gfx::Display::HasForceDeviceScaleFactor() ?
If there is a forced scale we should honor it.

[ananta, 2014-09-24 23:56:00]

https://codereview.chromium.org/600263002/diff/1/ui/gfx/win/dpi.cc
File ui/gfx/win/dpi.cc (right):

https://codereview.chromium.org/600263002/diff/1/ui/gfx/win/dpi.cc#newcode137
ui/gfx/win/dpi.cc:137: float dpi_scale =
gfx::Display::HasForceDeviceScaleFactor() ?
On 2014/09/24 23:51:15, sky wrote:
> If there is a forced scale we should honor it.

Thanks for catching that. Fixed

[sky, 2014-09-24 23:57:40]

LGTM

[scottmg, 2014-09-25 00:01:22]

With that, lgtm.

https://codereview.chromium.org/600263002/diff/20001/testing/buildbot/chromiu...
File testing/buildbot/chromium_win8_trybot.json (right):

https://codereview.chromium.org/600263002/diff/20001/testing/buildbot/chromiu...
testing/buildbot/chromium_win8_trybot.json:11: "content_browsertests",
I think this test needs to be added to 

https://code.google.com/p/chromium/codesearch#chromium/src/testing/buildbot/c...

too (I think that one is for the waterfall, whereas this one is trybots). I
admit I'm guessing though.

[ananta, 2014-09-25 00:17:06]

https://codereview.chromium.org/600263002/diff/20001/testing/buildbot/chromiu...
File testing/buildbot/chromium_win8_trybot.json (right):

https://codereview.chromium.org/600263002/diff/20001/testing/buildbot/chromiu...
testing/buildbot/chromium_win8_trybot.json:11: "content_browsertests",
On 2014/09/25 00:01:21, scottmg wrote:
> I think this test needs to be added to 
> 
>
https://code.google.com/p/chromium/codesearch#chromium/src/testing/buildbot/c...
> 
> too (I think that one is for the waterfall, whereas this one is trybots). I
> admit I'm guessing though.

Done.

[jam, 2014-09-25 00:42:22]

lgtm

https://codereview.chromium.org/600263002/diff/40001/testing/buildbot/chromiu...
File testing/buildbot/chromium.win.json (right):

https://codereview.chromium.org/600263002/diff/40001/testing/buildbot/chromiu...
testing/buildbot/chromium.win.json:335: "content_browsertests",
nit: tabbing?

[ananta, 2014-09-25 01:05:46]

https://codereview.chromium.org/600263002/diff/40001/testing/buildbot/chromiu...
File testing/buildbot/chromium.win.json (right):

https://codereview.chromium.org/600263002/diff/40001/testing/buildbot/chromiu...
testing/buildbot/chromium.win.json:335: "content_browsertests",
On 2014/09/25 00:42:22, jam wrote:
> nit: tabbing?

Done.

[ananta, 2014-09-25 01:07:15]

ananta@chromium.org changed reviewers:
+ dmazzoni@chromium.org

[ananta, 2014-09-25 01:07:28]

+dmazzoni for accessibility fixes.

[dmazzoni, 2014-09-25 17:17:46]

lgtm for accessibility

I filed http://crbug.com/417758 to remove the rest of the accessibility code
added just for win 8 support.

[ananta, 2014-09-25 18:05:51]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2014-09-25 18:07:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/600263002/80001

[commit-bot: I haz the power, 2014-09-25 21:11:44]

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

[commit-bot: I haz the power, 2014-09-25 21:11:45]

Try jobs failed on following builders:
  win_chromium_x64_rel_swarming on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[ananta, 2014-09-25 23:30:20]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2014-09-25 23:31:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/600263002/100001

[commit-bot: I haz the power, 2014-09-26 00:12:15]

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

[commit-bot: I haz the power, 2014-09-26 00:12:16]

Try jobs failed on following builders:
  linux_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu/builds/...)

[ananta, 2014-09-26 00:51:03]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2014-09-26 00:52:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/600263002/120001

[commit-bot: I haz the power, 2014-09-26 02:20:41]

Committed patchset #7 (id:120001) as b84b73abdacda8281b202ff2344abb3d414aab75

[commit-bot: I haz the power, 2014-09-26 02:21:18]

Patchset 7 (id:??) landed as
https://crrev.com/b1f9313020d4c1e8619f21b5320a0255bf313b4b
Cr-Commit-Position: refs/heads/master@{#296859}

[scottmg, 2014-09-26 02:42:55]

https://codereview.chromium.org/600263002/diff/120001/chrome/chrome.isolate
File chrome/chrome.isolate (right):

https://codereview.chromium.org/600263002/diff/120001/chrome/chrome.isolate#n...
chrome/chrome.isolate:72: '<(PRODUCT_DIR)/<(version_full).manifest',
duplicate block, just move the new file down here in a followup