[TaskScheduler]: Migrate off of AssertBlockingAllowedDeprecated in /ui/events

base::AssertBlockingAllowedDeprecated is deprecated in favor of
ScopedBlockingCall, which serves as a precise annotation of
the scope that may/will block.

Please make sure of the following:
  - ScopedBlockingCall is instantiated in a scope with minimal CPU usage.
    If this is not the case, ScopedBlockingCall should be instantiated
    closer to the blocking call. See scoped_blocking_call.h for more
    info. Please let me know when/where the blocking call happens if this needs
    to be changed.
  - Parameter |blocking_type| matches expectation:
      MAY_BLOCK: The call might block (e.g. file I/O that might hit in memory cache).
      WILL_BLOCK: The call will definitely block (e.g. cache already checked and now pinging
        server synchronously).
    See BlockingType for more info. While I assumed MAY_BLOCK by default, that might
    not be the best fit if we know that this callsite is guaranteed to block.
  - The ScopedBlockingCall's scope covers the entirety of the blocking operation
    previously asserted against by the AssertBlockingAllowed().
  - Calls to blocking //base APIs don't need to be annotated
    with ScopedBlockingCall. All blocking //base APIs (e.g. base::ReadFileToString, base::File::Read,
    base::SysInfo::AmountOfFreeDiskSpace, base::WaitableEvent::Wait, etc.) have their
    own internal annotations.

Refer to the top-level CL if necessary :
https://chromium-review.googlesource.com/c/chromium/src/+/1338391

Please CQ if LGTY!

This CL was uploaded by git cl split.

R=sadrul@chromium.org

Bug: 903957
Change-Id: I350657e7c0760b9ce1e4ff33a74a0e8e007d5e21
Reviewed-on: https://chromium-review.googlesource.com/c/1338409Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608823}

ui/events/devices/device_util_linux.cc

@@ -9,7 +9,6 @@
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/strings/string_util.h"
-#include "base/threading/thread_restrictions.h"
 
 namespace ui {
 
@@ -19,7 +18,6 @@ base::FilePath GetInputPathInSys(const base::FilePath& path) {
 }
 
 InputDeviceType GetInputDeviceTypeFromPath(const base::FilePath& path) {
-  base::AssertBlockingAllowedDeprecated();
   std::string event_node = path.BaseName().value();
   if (event_node.empty() ||
       !base::StartsWith(event_node, "event", base::CompareCase::SENSITIVE))