Bug 1750395 - Use mozshowdropdown events to show select dropdown. r=agi

After bug 1744009 Gecko will consistently fire these events. This allows
activating stuff via keyboard on Android like in every other OS (if you
have a keyboard attached of course) and is generally more consistent.

We remove MOZ_USE_NATIVE_POPUP_WINDOWS since it's unused.

Differential Revision: https://phabricator.services.mozilla.com/D136073

mobile/android/components/geckoview/GeckoViewPrompt.jsm

@@ -27,6 +27,10 @@ class PromptFactory {
 
   handleEvent(aEvent) {
     switch (aEvent.type) {
+      case "mozshowdropdown":
+      case "mozshowdropdown-sourcetouch":
+        this._handleSelect(aEvent);
+        break;
       case "click":
         this._handleClick(aEvent);
         break;
@@ -39,8 +43,14 @@ class PromptFactory {
     }
   }
 
+  // TODO(emilio): We should listen to MozOpenDateTimePicker instead, except
+  // the Gecko widget isn't supported for stuff like <input type=week>
   _handleClick(aEvent) {
     const target = aEvent.composedTarget;
+    if (ChromeUtils.getClassName(target) !== "HTMLInputElement") {
+      return;
+    }
+
     if (
       target.isContentEditable ||
       target.disabled ||
@@ -52,22 +62,16 @@ class PromptFactory {
       return;
     }
 
-    const win = target.ownerGlobal;
-    if (target instanceof win.HTMLSelectElement) {
-      this._handleSelect(target);
+    const type = target.type;
+    if (
+      type === "date" ||
+      type === "month" ||
+      type === "week" ||
+      type === "time" ||
+      type === "datetime-local"
+    ) {
+      this._handleDateTime(target, type);
       aEvent.preventDefault();
-    } else if (target instanceof win.HTMLInputElement) {
-      const type = target.type;
-      if (
-        type === "date" ||
-        type === "month" ||
-        type === "week" ||
-        type === "time" ||
-        type === "datetime-local"
-      ) {
-        this._handleDateTime(target, type);
-        aEvent.preventDefault();
-      }
     }
   }
 

mobile/android/components/geckoview/GeckoViewStartup.jsm

@@ -41,6 +41,8 @@ const JSWINDOWACTORS = {
       events: {
         click: { capture: false, mozSystemGroup: true },
         contextmenu: { capture: false, mozSystemGroup: true },
+        mozshowdropdown: {},
+        "mozshowdropdown-sourcetouch": {},
         DOMPopupBlocked: { capture: false, mozSystemGroup: true },
       },
     },

toolkit/moz.configure

@@ -2578,14 +2578,6 @@ set_config("ANDROID_PACKAGE_NAME", android_package_name)
 option(env="MOZ_WINCONSOLE", nargs="?", help="Whether we can create a console window.")
 set_define("MOZ_WINCONSOLE", True, when=depends("MOZ_WINCONSOLE")(lambda x: x))
 
-option(
-    env="MOZ_USE_NATIVE_POPUP_WINDOWS",
-    default=target_is_android,
-    help="Whether to use native popup windows",
-)
-
-set_define("MOZ_USE_NATIVE_POPUP_WINDOWS", True, when="MOZ_USE_NATIVE_POPUP_WINDOWS")
-
 
 # Alternative Crashreporter setting
 option(