Allow base::{Time,TimeDelta,TimeTicks} in Blink.

As of crrev.com/531516, all of the WTF counterparts of those base
classes are now simple aliases to the base ones. Now, we can start
using the base classes in Blink.

Bug: 763980, 794845
Change-Id: Ica8d81549ed6d7fd4f56ed03d22562c973e8a00e
Reviewed-on: https://chromium-review.googlesource.com/886041Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Yuta Kitamura <yutak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531841}

third_party/WebKit/Source/DEPS

@@ -8,6 +8,7 @@ include_rules = [
     "+base/macros.h",
     "+base/memory/ptr_util.h",
     "+base/memory/weak_ptr.h",
+    "+base/time/time.h",
     "+build",
     "+services/service_manager/public/cpp/connector.h",
     "+services/service_manager/public/cpp/interface_provider.h",

third_party/WebKit/Tools/Scripts/audit-non-blink-usage.py

@@ -35,6 +35,9 @@ _CONFIG = [
             'base::MakeRefCounted',
             'base::Optional',
             'base::SingleThreadTaskRunner',
+            'base::Time',
+            'base::TimeDelta',
+            'base::TimeTicks',
             'base::UnguessableToken',
             'base::WeakPtr',
             'base::WeakPtrFactory',