[fsp] Add notifications in case of slow operations.

[fsp] Add notifications in case of slow operations.

Previously, every request was aborted automatically if it took more than 10
seconds. However, for remote file systems using eg HTTP, on slow connection
operation can take longer.

Another situation is when a providing extension shows a dialog for eg.
password or credentials. We don't want to abort an operation in such case.

This CL introduces a notification which is shown when an operation takes
longer than expected. Users can abort the operation by clicking on the
'ABORT' button.

TEST=unit_tests: *FileSystemProvider*Timeout*
BUG=248427
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=279541

[mtomasz, 2014-06-23 08:28:25]

@kinaba: PTAL. Thanks.

[kinaba, 2014-06-24 05:56:17]

lgtm

[mtomasz, 2014-06-24 05:59:55]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-06-24 06:01:22]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/350683002/40001

[commit-bot: I haz the power, 2014-06-24 06:28:45]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_aosp on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_aosp/builds/8...)
  android_chromium_gn_compile_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_chromium_gn_c...)
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/19...)
  chromium_presubmit on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/chromium_presubmit/bu...)
  ios_dbg_simulator on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_dbg_simulator/bui...)
  ios_rel_device on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_rel_device/builds...)
  ios_rel_device_ninja on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_rel_device_ninja/...)
  linux_chromium_chromeos_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_chromeos_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_clang_...)
  linux_chromium_gn_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_gn_rel...)
  linux_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_rel/bu...)
  mac_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_compile_...)
  mac_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_rel/buil...)
  win_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_compile_...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)
  win_chromium_x64_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_x64_rel/...)
  linux_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu/builds/...)
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/20707)

[commit-bot: I haz the power, 2014-06-24 06:30:34]

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

[commit-bot: I haz the power, 2014-06-24 06:30:35]

Try jobs failed on following builders:
  ios_dbg_simulator on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_dbg_simulator/bui...)
  ios_rel_device on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_rel_device/builds...)
  ios_rel_device_ninja on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_rel_device_ninja/...)
  mac_chromium_compile_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_compile_...)
  mac_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_rel/buil...)
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/20716)

[mtomasz, 2014-06-24 07:16:57]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-06-24 07:18:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/350683002/60001

[commit-bot: I haz the power, 2014-06-24 09:17:16]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_chromium_chromeos_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_gn_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_gn_rel...)
  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, 2014-06-24 09:29:38]

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

[commit-bot: I haz the power, 2014-06-24 09:29:39]

Try jobs failed on following builders:
  linux_chromium_chromeos_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)

[mtomasz, 2014-06-24 10:01:51]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-06-24 10:02:54]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/350683002/80001

[commit-bot: I haz the power, 2014-06-24 13:00:49]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  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, 2014-06-24 14:00:18]

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

[commit-bot: I haz the power, 2014-06-24 14:00:19]

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

[mtomasz, 2014-06-24 14:02:30]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-06-24 14:05:17]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/350683002/80001

[commit-bot: I haz the power, 2014-06-24 14:37:02]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  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, 2014-06-24 15:17:01]

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

[commit-bot: I haz the power, 2014-06-24 15:17:01]

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

[mtomasz, 2014-06-24 23:11:42]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-06-24 23:14:31]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/350683002/80001

[commit-bot: I haz the power, 2014-06-24 23:16:48]

Change committed as 279541