Implement UnitTestSupport::readFromFile

Implement UnitTestSupport::readFromFile

This allows us to remove all PlatformFileHandle related code
in Blink core.

(Blink side patch: https://codereview.chromium.org/22645008/)

BUG=267341
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=216981

[kinuko, 2013-08-09 11:08:09]

James, some WebKit unit tests rely on platform/FileSystem.h methods which use
raw platform file handle (openFile, closeFile, readFromFile) and I want to
deprecate them. Can I add a method like this in WebKitUnitTestSupport?

If this patch lands we can do this in blink side:
https://codereview.chromium.org/22645008/

[jamesr, 2013-08-09 23:10:13]

I think the idea is fine.  Patch lgtm, although I think we can simplify this by
using file_util

https://codereview.chromium.org/22738002/diff/1005/webkit/support/test_webkit...
File webkit/support/test_webkit_platform_support.cc (right):

https://codereview.chromium.org/22738002/diff/1005/webkit/support/test_webkit...
webkit/support/test_webkit_platform_support.cc:357: base::PlatformFile handle =
base::CreatePlatformFile(
instead of all this, could we just use file_util::ReadFileToString()? We can't
do any useful error recovery in a unit test anyway

[kinuko, 2013-08-12 02:43:09]

https://codereview.chromium.org/22738002/diff/1005/webkit/support/test_webkit...
File webkit/support/test_webkit_platform_support.cc (right):

https://codereview.chromium.org/22738002/diff/1005/webkit/support/test_webkit...
webkit/support/test_webkit_platform_support.cc:357: base::PlatformFile handle =
base::CreatePlatformFile(
On 2013/08/09 23:10:13, jamesr wrote:
> instead of all this, could we just use file_util::ReadFileToString()? We can't
> do any useful error recovery in a unit test anyway

I wasn't motivated to use ReadFileToString because we expect binary data here...
but on the second thought I realized what it does exactly does what's needed
here.

Ok, done.

[commit-bot: I haz the power, 2013-08-12 03:58:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinuko@chromium.org/22738002/47001

[commit-bot: I haz the power, 2013-08-12 10:48:45]

Retried try job too often on win_rel for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2013-08-12 11:26:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinuko@chromium.org/22738002/47001

[commit-bot: I haz the power, 2013-08-12 13:13:05]

Change committed as 216981