Add disallowPositionReuse

spec.bs

@@ -115,6 +115,7 @@ dictionary DocumentPictureInPictureOptions {
   [EnforceRange] unsigned long long width = 0;
   [EnforceRange] unsigned long long height = 0;
   boolean disallowReturnToOpener = false;
+  boolean ignorePreviousWindowBounds = false;
 };
 
 [Exposed=Window, SecureContext]
@@ -219,6 +220,12 @@ problems.
         window such that the distance between the top and bottom edges of the
         viewport are |options|["{{DocumentPictureInPictureOptions/height}}"]
         pixels.
+<p class="note">
+If |options|["{{DocumentPictureInPictureOptions/ignorePreviousWindowBounds}}"]
+exists and is true, then the user agent may use this hint to prefer behavior
+that is similar to steps 12 and 13, rather than considering any previous
+position or size of any previously closed |pip traversable| window.
+</p>
 14. If |options|["{{DocumentPictureInPictureOptions/disallowReturnToOpener}}"] exists
     and is <code>true</code>, the user agent should not display UI affordances
     on the picture-in-picture window that allow the user to return to the
@@ -667,7 +674,33 @@ picture-in-picture experience. Use the
 button.
 
 <pre class="lang-javascript">
-documentPictureInPicture.requestWindow({ disallowReturnToOpener: true });
+documentPictureInPicture.requestWindow({
+  disallowReturnToOpener: true
+}).then(...);
+</pre>
+
+## Ignore previous window bounds ## {#example-ignore-previous-window-bounds}
+
+While a document picture-in-picture window is opened, the user may choose
+to resize or reposition it. If the document picture-in-picture window is
+closed, then reopened later, the user agent may use the previous position
+and size as a hint for where to place the new window.
+
+The site can provide a hint to the user agent that reusing the previous
+document picture-in-picture window position and size is not desirable
+by setting the {{DocumentPictureInPictureOptions/ignorePreviousWindowBounds}}
+option to true.  For example, if the site is requesting the new document picture-in-
+picture window for an unrelated activity from the previous one, then the site
+might provide this hint to the user agent.  In response, the user agent may
+choose to use the default position, the default size, or the size hint
+provided by the site instead.
+
+<pre class="lang-javascript">
+documentPictureInPicture.requestWindow({
+  ignorePreviousWindowBounds: true,
+  width: 320,
+  height: 480
+}).then(...);
 </pre>
 
 # Acknowledgments # {#acknowledgments}