Bug 1459260 - Don't use dom.meta-viewport.enabled in tests that don't need it. r=kats

Many tests only had it enabled because it was required for zooming to work on
desktop. This patch revises tests to only use it if they actually use a non-
default meta viewport tag.

The motivation is to bring test coverage closer to the platform defaults (so
on desktop, tests will run with dom.meta-viewport.enabled=false, and on Android
with dom.meta-viewport.enabled=true, matching the production scenarios).

Depends on D30988

Differential Revision: https://phabricator.services.mozilla.com/D30989

--HG--
extra : moz-landing-system : lando

gfx/layers/apz/test/mochitest/apz_test_utils.js

@@ -801,8 +801,6 @@ function getPrefs(ident) {
         // position is synced back to the main thread. So we disable displayport
         // expiry for these tests.
         ["apz.displayport_expiry_ms", 0],
-        // All of test cases should define viewport meta tag.
-        ["dom.meta-viewport.enabled", true],
       ];
     case "TOUCH_ACTION":
       return [

gfx/layers/apz/test/mochitest/test_group_minimum_scale_size.html

@@ -27,8 +27,8 @@ const prefs = [
   // Explicitly enable pinch-zooming, so this test can run on desktop
   // even though zooming isn't enabled by default on desktop yet.
   ["apz.allow_zooming", true],
-  // Pinch-zooming currently requires meta viewport support (this requirement
-  // will eventually be removed).
+  // Similarly, explicitly enable support for meta viewport tags (which the
+  // test cases use) so they're processed even on desktop.
   ["dom.meta-viewport.enabled", true],
   // We use the Visual Viewport API to tell the visual viewport offset.
   ["dom.visualviewport.enabled", true],

gfx/layers/apz/test/mochitest/test_group_touchevents-2.html

@@ -13,7 +13,6 @@ var isWindows = getPlatform() == "windows";
 
 const shared_prefs = [
   ["apz.test.fails_with_native_injection", isWindows],
-  ["dom.meta-viewport.enabled", true],
   ["dom.w3c_touch_events.legacy_apis.enabled", true],
 ];
 

gfx/layers/apz/test/mochitest/test_group_touchevents-3.html

@@ -10,10 +10,11 @@
   <script type="application/javascript">
 
 var touch_action_prefs = getPrefs("TOUCH_ACTION");
+var with_meta_viewport = [...touch_action_prefs, ["dom.meta-viewport.enabled", true]];
 
 var subtests = [
   // Simple test to exercise touch-action CSS property
-  {"file": "helper_touch_action.html", "prefs": touch_action_prefs},
+  {"file": "helper_touch_action.html", "prefs": with_meta_viewport},
   // More complex touch-action tests, with overlapping regions and such
   {"file": "helper_touch_action_complex.html", "prefs": touch_action_prefs},
   // Tests that touch-action CSS properties are handled in APZ without waiting

gfx/layers/apz/test/mochitest/test_group_touchevents-4.html

@@ -9,14 +9,14 @@
   <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
   <script type="application/javascript">
 
-var basic_pan_prefs = getPrefs("TOUCH_EVENTS:PAN");
 var touch_action_prefs = getPrefs("TOUCH_ACTION");
 
 var subtests = [
   // clicking on element with :active::after CSS property
-  {"file": "helper_bug1473108.html", "prefs": [["dom.meta-viewport.enabled", true]]},
+  {"file": "helper_bug1473108.html"},
   // Resetting isFirstPaint shouldn't clobber the visual viewport
-  {"file": "helper_bug1509575.html", "prefs": basic_pan_prefs},
+  {"file": "helper_bug1509575.html", "prefs": [["dom.meta-viewport.enabled", true],
+                                               ...getPrefs("TOUCH_EVENTS:PAN")]},
   // Exercise one of the main-thread touch-action determination codepaths.
   {"file": "helper_bug1506497_touch_action_fixed_on_fixed.html", "prefs": touch_action_prefs},
   // Add new subtests here. If this starts timing out because it's taking too

gfx/layers/apz/test/mochitest/test_group_touchevents.html

@@ -18,19 +18,17 @@ var subtests = [
   {"file": "helper_iframe_pan.html", "prefs": basic_pan_prefs},
 
   // Simple test to exercise touch-tapping behaviour
-  {"file": "helper_tap.html", "prefs": [["dom.meta-viewport.enabled", true]]},
+  {"file": "helper_tap.html"},
   // Tapping, but with a full-zoom applied
-  {"file": "helper_tap_fullzoom.html", "prefs": [["dom.meta-viewport.enabled", true]]},
+  {"file": "helper_tap_fullzoom.html"},
 
   // For the following two tests, disable displayport suppression to make sure it
   // doesn't interfere with the test by scheduling paints non-deterministically.
   {"file": "helper_scrollto_tap.html?true",
-   "prefs": [["apz.paint_skipping.enabled", true],
-             ["dom.meta-viewport.enabled", true]],
+   "prefs": [["apz.paint_skipping.enabled", true]],
    "dp_suppression": false},
   {"file": "helper_scrollto_tap.html?false",
-   "prefs": [["apz.paint_skipping.enabled", false],
-             ["dom.meta-viewport.enabled", true]],
+   "prefs": [["apz.paint_skipping.enabled", false]],
    "dp_suppression": false},
 
   // Add new subtests to test_group_touch_events-4.html, not this file.

gfx/layers/apz/test/mochitest/test_group_zoom.html

@@ -29,8 +29,8 @@ var prefs = [
   // Explicitly enable pinch-zooming, so this test can run on desktop
   // even though zooming isn't enabled by default on desktop yet.
   ["apz.allow_zooming", true],
-  // Pinch-zooming currently requires meta viewport support (this requirement
-  // will eventually be removed).
+  // Similarly, explicitly enable support for meta viewport tags (which the
+  // test cases use) so they're processed even on desktop.
   ["dom.meta-viewport.enabled", true],
   // Increase the content response timeout because some tests do preventDefault
   // and we want to make sure APZ actually waits for them.