emulation.setScriptingEnabled (#946)

`emulation. setScriptingEnabled` command. Related [HTML PR](whatwg/html#11441) should be landed after this one.

* Store the state in `scripting enabled overrides map`.
* Provide a hook "WebDriver BiDi scripting is enabled" to be called by HTML's ["Scripting is enabled"](https://html.spec.whatwg.org/multipage/webappapis.html#concept-environment-script) method.
* Force scripting enabled for scripts initiated by BiDi protocol user via "bypassDisabledScripting" argument.

Author: sadym-chromium

index.bs

@@ -3143,6 +3143,9 @@ A [=remote end=] has a <dfn>timezone overrides map</dfn> which is a weak map bet
 A [=remote end=] has an <dfn>unhandled prompt behavior overrides map</dfn> which is a
 weak map between [=user contexts=] and [=unhandled prompt behavior struct=].
 
+A [=remote end=] has a <dfn>scripting enabled overrides map</dfn> which is a weak
+map between [=navigables=] or [=user contexts=] and boolean or null.
+
 ### Types ### {#module-browsingcontext-types}
 
 #### The browsingContext.BrowsingContext Type #### {#type-browsingContext-Browsingcontext}
@@ -5823,6 +5826,7 @@ EmulationCommand = (
   emulation.SetGeolocationOverride //
   emulation.SetLocaleOverride //
   emulation.SetScreenOrientationOverride //
+  emulation.SetScriptingEnabled //
   emulation.SetTimezoneOverride
 )
 </pre>
@@ -6273,6 +6277,110 @@ The [=remote end steps=] with |command parameters| are:
 
 </div>
 
+#### The emulation.setScriptingEnabled Command ####  {#command-emulation-setScriptingEnabled}
+
+The <dfn export for=commands>emulation.setScriptingEnabled</dfn> command emulates
+disabling JavaScript on web pages.
+
+<dl>
+   <dt>Command Type</dt>
+   <dd>
+    <pre class="cddl" data-cddl-module="remote-cddl">
+      emulation.SetScriptingEnabled = (
+        method: "emulation.setScriptingEnabled",
+        params: emulation.SetScriptingEnabledParameters
+      )
+
+      emulation.SetScriptingEnabledParameters = {
+        enabled: false / null,
+        ? contexts: [+browsingContext.BrowsingContext],
+        ? userContexts: [+browser.UserContext],
+      }
+    </pre>
+   </dd>
+   <dt>Result Type</dt>
+   <dd>
+    <code>
+     EmptyResult
+    </code>
+   </dd>
+</dl>
+
+Note: only emulation of disabled Javascript is supported.
+
+<div algorithm>
+The <dfn export>WebDriver BiDi scripting is enabled</dfn> steps given
+[=environment settings object=] |settings| are:
+
+1. Let |navigable| be |settings|'s [=relevant global object=]'s
+   <a>associated <code>Document</code></a>'s [=/node navigable=].
+
+1. Let |top-level traversable| be |navigable|’s [=navigable/top-level traversable=].
+
+1. If [=scripting enabled overrides map=] contains |top-level traversable|:
+
+   1. If [=scripting enabled overrides map=][|top-level traversable|] is false,
+      return false.
+
+   1. Return true.
+
+1. Let |user context| be  |top-level traversable|'s [=associated user context=].
+
+1. If [=scripting enabled overrides map=] contains |user context|, return
+   [=scripting enabled overrides map=][|user context|].
+
+   1. If [=scripting enabled overrides map=][|user context|] is false, return false.
+
+   1. Return true.
+
+1. Return true.
+
+</div>
+
+<div algorithm="remote end steps for emulation.setScriptingEnabled">
+
+The [=remote end steps=] with |command parameters| are:
+
+1. If |command parameters| [=map/contains=] "<code>userContexts</code>"
+   and |command parameters| [=map/contains=] "<code>context</code>",
+   return [=error=] with [=error code=] [=invalid argument=].
+
+1. If |command parameters| doesn't [=map/contain=] "<code>userContexts</code>"
+   and |command parameters| doesn't [=map/contain=] "<code>context</code>",
+   return [=error=] with [=error code=] [=invalid argument=].
+
+1. Let |emulated scripting enabled status| be null.
+
+1. If |command parameters| [=map/contains=] "<code>enabled</code>":
+
+   1. Set |emulated scripting enabled status| to
+      |command parameters|["<code>enabled</code>"].
+
+1. If the <code>contexts</code> field of |command parameters| is present:
+
+   1. Let |navigables| be the result of [=trying=] to
+      [=get valid top-level traversables by ids=] with
+      |command parameters|["<code>contexts</code>"].
+
+   1. For each |navigable| of |navigables|:
+
+      1. [=map/Set=] [=scripting enabled overrides map=][|navigable|] to
+         |emulated scripting enabled status|.
+
+1. If the <code>userContexts</code> field of |command parameters| is present:
+
+   1. Let |user contexts| be the result of [=trying=] to [=get valid user contexts=]
+      with |command parameters|["<code>userContexts</code>"].
+
+   1. For each |user context| of |user contexts|:
+
+      1. [=map/Set=] [=scripting enabled overrides map=][|user context|] to
+         |emulated scripting enabled status|.
+
+1. Return [=success=] with data null.
+
+</div>
+
 #### The emulation.setTimezoneOverride Command ####  {#command-emulation-setTimezoneOverride}
 
 The <dfn export for=commands>emulation.setTimezoneOverride</dfn> command modifies
@@ -11791,11 +11899,14 @@ To <dfn>evaluate function body</dfn> given |function declaration|,
 
 Note: the |function declaration| is parenthesized and evaluated.
 
+1. Let |bypassDisabledScripting| be true.
+
 1. Let |parenthesized function declaration| be [=concatenate=]
    «"<code>(</code>", |function declaration|, "<code>)</code>"»
 
 1. Let |function script| be the result of [=create a classic script=] with
-   |parenthesized function declaration|, |environment settings|, |base URL|, and |options|.
+   |parenthesized function declaration|, |environment settings|, |base URL|,
+   |options| and |bypassDisabledScripting|.
 
 1. [=Prepare to run script=] with |environment settings|.
 
@@ -11981,8 +12092,10 @@ The [=remote end steps=] given |session| and |command parameters| are:
 
 1. Let |base URL| be the [=API base URL=] of |environment settings|.
 
+1. Let |bypassDisabledScripting| be true.
+
 1. Let |script| be the result of [=create a classic script=] with |source|,
-   |environment settings|, |base URL|, and |options|.
+   |environment settings|, |base URL|, |options| and |bypassDisabledScripting|.
 
 1. If |command parameters|["<code>userActivation</code>"] is true, run [=activation notification=] steps.