Bug 1649530: Deprecate GeckoRuntimeSettings for toggling multiprocess; r=geckoview-reviewers,agi

I intend to uplift this patch to v79, so the changelog references 79 and the
version for removal is indicated as v82.

Differential Revision: https://phabricator.services.mozilla.com/D82033

mobile/android/geckoview/api.txt

@@ -574,7 +574,7 @@ package org.mozilla.geckoview {
     method @Nullable public Rect getScreenSizeOverride();
     method @Nullable public RuntimeTelemetry.Delegate getTelemetryDelegate();
     method public boolean getUseMaxScreenDepth();
-    method public boolean getUseMultiprocess();
+    method @Deprecated public boolean getUseMultiprocess();
     method public boolean getWebFontsEnabled();
     method public boolean getWebManifestEnabled();
     method @NonNull public GeckoRuntimeSettings setAboutConfigEnabled(boolean);
@@ -627,7 +627,7 @@ package org.mozilla.geckoview {
     method @NonNull public GeckoRuntimeSettings.Builder screenSizeOverride(int, int);
     method @NonNull public GeckoRuntimeSettings.Builder telemetryDelegate(@NonNull RuntimeTelemetry.Delegate);
     method @NonNull public GeckoRuntimeSettings.Builder useMaxScreenDepth(boolean);
-    method @NonNull public GeckoRuntimeSettings.Builder useMultiprocess(boolean);
+    method @Deprecated @NonNull public GeckoRuntimeSettings.Builder useMultiprocess(boolean);
     method @NonNull public GeckoRuntimeSettings.Builder webFontsEnabled(boolean);
     method @NonNull public GeckoRuntimeSettings.Builder webManifest(boolean);
     method @NonNull protected GeckoRuntimeSettings newSettings(@Nullable GeckoRuntimeSettings);

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoRuntimeSettings.java

@@ -48,7 +48,11 @@ public final class GeckoRuntimeSettings extends RuntimeSettings {
          * @param use A flag determining whether multiprocess should be enabled.
          *            Default is true.
          * @return This Builder instance.
+         *
+         * @deprecated This method will be removed in GeckoView 82, at which point GeckoView will
+         *             only operate in multiprocess mode.
          */
+        @Deprecated // Bug 1650118
         public @NonNull Builder useMultiprocess(final boolean use) {
             getSettings().mUseMultiprocess.set(use);
             return this;
@@ -574,7 +578,11 @@ public final class GeckoRuntimeSettings extends RuntimeSettings {
      * Whether multiprocess is enabled.
      *
      * @return true if multiprocess is enabled, false otherwise.
+     *
+     * @deprecated This method will be removed in GeckoView 82, at which point GeckoView will only
+     *             operate in multiprocess mode.
      */
+    @Deprecated // Bug 1650118
     public boolean getUseMultiprocess() {
         return mUseMultiprocess.get();
     }

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/doc-files/CHANGELOG.md

@@ -36,12 +36,17 @@ to allow adding gecko profiler markers.
 ([bug 1624993]({{bugzilla}}1624993))
 - ⚠️ Deprecated `Parcelable` support in `GeckoSession` with the intention of removing
   in GeckoView v82. ([bug 1649529]({{bugzilla}}1649529))
+- ⚠️ Deprecated [`GeckoRuntimeSettings.Builder.useMultiprocess`][79.6] and
+  [`GeckoRuntimeSettings.getUseMultiprocess`][79.7] with the intention of removing
+  them in GeckoView v82. ([bug 1649530]({{bugzilla}}1649530))
 
 [79.1]: {{javadoc_uri}}/WebExtension.TabDelegate.html#onOpenOptionsPage-org.mozilla.geckoview.WebExtension-
 [79.2]: {{javadoc_uri}}/WebNotification.html#source
 [79.3]: {{javadoc_uri}}/WebExtensionController.html#ensureBuiltIn-java.lang.String-java.lang.String-
 [79.4]: {{javadoc_uri}}/ProfilerController.html
 [79.5]: {{javadoc_uri}}/GeckoRuntime.html#getProfilerController--
+[79.6]: {{javadoc_uri}}/GeckoRuntimeSettings.Builder.html#useMultiprocess-boolean-
+[79.7]: {{javadoc_uri}}/GeckoRuntimeSettings.html#getUseMultiprocess--
 
 ## v78
 - Added [`WebExtensionController.installBuiltIn`][78.1] that allows installing an
@@ -742,4 +747,4 @@ to allow adding gecko profiler markers.
 [65.24]: {{javadoc_uri}}/CrashReporter.html#sendCrashReport-android.content.Context-android.os.Bundle-java.lang.String-
 [65.25]: {{javadoc_uri}}/GeckoResult.html
 
-[api-version]: 3bf9118a008a2a172964a13ba3f79ff59fe1f77e
+[api-version]: 41921b808dd64b6d85929aa7f52031cc762605f9