Change "global monotonic clock" to "universal"

"global" is a term already used to describe the global
object, while this monotonic clock is shared across globals
(e.g. workers and the window).

Also expose "current universal time", for use by Fetch.
See whatwg/fetch#1185

index.html

@@ -259,17 +259,17 @@ <h3>Time Origin</h3>
       <li>Assert that <var>global</var>'s <a>time origin</a> is not undefined.
       </li>
       <li>Let <var>t1</var> be the {{DOMHighResTimeStamp}} representing the
-      high resolution time at which the <a>global monotonic clock</a> is zero.
+      high resolution time at which the <a>universal monotonic clock</a> is zero.
       </li>
       <li>Let <var>t2</var> be the {{DOMHighResTimeStamp}} representing the
-      high resolution time value of the <a>global monotonic clock</a> at <var>
+      high resolution time value of the <a>universal monotonic clock</a> at <var>
         global</var>'s <a>time origin</a>.
       </li>
       <li>Return the sum of <var>t1</var> and <var>t2</var>.</li>
     </ul>
     <p class="note">The <a>time origin timestamp</a> and the value returned by
     <a>Date.now()</a> executed at "zero time" can differ because the former is
-    recorded with respect to a global monotonic clock that is not subject to
+    recorded with respect to a universal monotonic clock that is not subject to
     system and user clock adjustments, clock skew, and so on—see <a href=
     "#sec-monotonic-clock"></a>.</p>
     <p>
@@ -286,7 +286,7 @@ <h3>Time Origin</h3>
     <p>The <dfn data-export="">current high resolution time</dfn> given a 
     [=/global object=] |current global| must run the following steps:
     <ul>
-      <li>Let |current time| be the present time.</li>
+      <li>Let |current time| be the |current universal time|.</li>
       <li>Let |settings object| be |current global|'s [=relevant settings object=].</li>
       <li>Let |time resolution| be 100 microseconds, or a higher
         <a>implementation-defined</a> value.</li>
@@ -300,11 +300,13 @@ <h3>Time Origin</h3>
       <li>Return the result of [=relative high resolution time=] given
         |current time| and |current global|.</li>
     </ul>
+    <p>The <dfn data-export="">current universal time</dfn> is the value
+    of the |universal monotonic clock|.
   </section>
   <section id="sec-domhighrestimestamp">
     <h3>The <dfn data-export="">DOMHighResTimeStamp</dfn> typedef</h3>
     <p>The {{DOMHighResTimeStamp}} type is used to store a time value in
-    milliseconds, measured relative from the <a>time origin</a>, <a>global
+    milliseconds, measured relative from the <a>time origin</a>, <a>universal
     monotonic clock</a>, or a time value that represents a duration between two
     {{DOMHighResTimeStamp}}s.</p>
     <pre class='idl'>
@@ -371,16 +373,16 @@ <h3>Monotonic Clock</h3>
     time values have the same <a>time origin</a>.</p>
     <p data-link-for="Performance" data-tests='test_cross_frame_start.html'>The time values returned when
     getting <code>performance.</code>{{timeOrigin}} MUST use the same <dfn data-export=
-    "">global monotonic clock</dfn> that is shared by <a>time origin</a>s, is
+    "">universal monotonic clock</dfn> that is shared by <a>time origin</a>s, is
     monotonically increasing and not subject to system clock adjustments or
     system clock skew, and whose reference point is the [[ECMA-262]]
     <dfn data-no-export="" data-cite=
     "ECMA-262#sec-time-values-and-time-range">time</dfn> definition - see
     [[[#sec-privacy-security]]].</p>
-    <p class="note">The user agent can reset its global monotonic clock across
+    <p class="note">The user agent can reset its universal monotonic clock across
     browser restarts, or whenever starting an isolated browsing session—e.g.
     incognito or similar browsing mode. As a result, developers should not use
-    global timestamps as absolute time that holds its monotonic properties
+    universal timestamps as absolute time that holds its monotonic properties
     across all past, present, and future contexts; in practice, the monotonic
     properties only apply for contexts that can reach each other by exchanging
     messages via one of the provided messaging mechanisms - e.g. `postMessage`,
@@ -456,22 +458,22 @@ <h3>Clock resolution</h3>
       <h3>Clock drift</h3>
       <p>This specification also defines an API that provides sub-millisecond
       time resolution of the zero time of the time origin, which requires and
-      exposes a <a>global monotonic clock</a> to the application, and that must
-      be shared across all the browser contexts. The <a>global monotonic
+      exposes a <a>universal monotonic clock</a> to the application, and that must
+      be shared across all the browser contexts. The <a>universal monotonic
       clock</a> does not need to be tied to physical time, but is recommended
       to be set with respect to the [[ECMA-262]] definition of <a>time</a> to
       avoid exposing new fingerprint entropy about the user — e.g. this time
       can already be easily obtained by the application, whereas exposing a new
       logical clock provides new information.</p>
-      <p>However, even with the above mechanism in place, the <a>global
+      <p>However, even with the above mechanism in place, the <a>universal
       monotonic clock</a> may provide additional <a href=
       "https://en.wikipedia.org/wiki/Clock_drift">clock drift</a> resolution.
       Today, the application can timestamp the time-of-day and monotonic time
       values (via <a>Date.now()</a> and {{Performance.now()}}) at multiple
       points within the same context and observe drift between them—e.g. due to
       automatic or user clock adjustments. With the {{Performance.timeOrigin}}
       attribute, the attacker can also compare the time at which <a>time
-      origin</a> is zero, as reported by the <a>global monotonic clock</a>,
+      origin</a> is zero, as reported by the <a>universal monotonic clock</a>,
       against the current time-of-day estimate of when it is zero (i.e. the
       difference between `Date.now()-performance.now()` and
       `performance.timeOrigin`) and potentially observe clock drift between