inspector: Drop usage of WTF::Mutex::TimedWait in favour of Wait.

This code only ever waits not at all (equivalent to doing nothing) or forever
(equivalent to using Wait), so drop TimedWait. This both makes the code simpler
and clearer, and drops the only usage of the WTF::Mutex "absolute time" semantics.
This helps clear the path for adopting base-style semantics for TimedWait instead.

Bug: 856641
Change-Id: I912b01b475173b965c7990cb4d3476c2eb21fae5
Reviewed-on: https://chromium-review.googlesource.com/1183592Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Jeremy Roman <jbroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587698}

third_party/blink/renderer/core/inspector/inspector_task_runner.cc

@@ -85,18 +85,15 @@ bool InspectorTaskRunner::IsRunningTask() {
 InspectorTaskRunner::Task InspectorTaskRunner::TakeNextTask(
     InspectorTaskRunner::WaitMode wait_mode) {
   MutexLocker lock(mutex_);
-  bool timed_out = false;
 
-  static double infinite_time = std::numeric_limits<double>::max();
-  double absolute_time = wait_mode == kWaitForTask ? infinite_time : 0.0;
-  while (!disposed_ && !timed_out && queue_.IsEmpty())
-    timed_out = !condition_.TimedWait(mutex_, absolute_time);
-  DCHECK(!timed_out || absolute_time != infinite_time);
+  if (wait_mode == kWaitForTask) {
+    while (!disposed_ && queue_.IsEmpty())
+      condition_.Wait(mutex_);
+  }
 
-  if (disposed_ || timed_out)
+  if (disposed_ || queue_.IsEmpty())
     return Task();
 
-  SECURITY_DCHECK(!queue_.IsEmpty());
   return queue_.TakeFirst();
 }