Bug 1290420 Part 3: Set the metaViewportOverride flag when viewing a device with touch event support in Responsive Design Mode. r=gl

Depends on D3375

Differential Revision: https://phabricator.services.mozilla.com/D3376

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

devtools/client/responsive.html/manager.js

@@ -638,12 +638,19 @@ ResponsiveUI.prototype = {
    *         Whether a reload is needed to apply the change.
    */
   updateTouchSimulation(enabled) {
-    if (!enabled) {
-      return this.emulationFront.clearTouchEventsOverride();
+    let reloadNeeded;
+    if (enabled) {
+      reloadNeeded = this.emulationFront.setTouchEventsOverride(
+        Ci.nsIDocShell.TOUCHEVENTS_OVERRIDE_ENABLED
+      );
+      reloadNeeded |= this.emulationFront.setMetaViewportOverride(
+        Ci.nsIDocShell.META_VIEWPORT_OVERRIDE_ENABLED
+      );
+    } else {
+      reloadNeeded = this.emulationFront.clearTouchEventsOverride();
+      reloadNeeded |= this.emulationFront.clearMetaViewportOverride();
     }
-    return this.emulationFront.setTouchEventsOverride(
-      Ci.nsIDocShell.TOUCHEVENTS_OVERRIDE_ENABLED
-    );
+    return reloadNeeded;
   },
 
   /**

devtools/server/actors/emulation.js

@@ -206,6 +206,33 @@ const EmulationActor = protocol.ActorClassWithSpec(emulationSpec, {
     return false;
   },
 
+  /* Meta viewport override */
+
+  _previousMetaViewportOverride: undefined,
+
+  setMetaViewportOverride(flag) {
+    if (this.getMetaViewportOverride() == flag) {
+      return false;
+    }
+    if (this._previousMetaViewportOverride === undefined) {
+      this._previousMetaViewportOverride = this.getMetaViewportOverride();
+    }
+
+    this.docShell.metaViewportOverride = flag;
+    return true;
+  },
+
+  getMetaViewportOverride() {
+    return this.docShell.metaViewportOverride;
+  },
+
+  clearMetaViewportOverride() {
+    if (this._previousMetaViewportOverride !== undefined) {
+      return this.setMetaViewportOverride(this._previousMetaViewportOverride);
+    }
+    return false;
+  },
+
   /* User agent override */
 
   _previousUserAgentOverride: undefined,

devtools/shared/specs/emulation.js

@@ -78,6 +78,29 @@ const emulationSpec = generateActorSpec({
       }
     },
 
+    setMetaViewportOverride: {
+      request: {
+        flag: Arg(0, "number")
+      },
+      response: {
+        valueChanged: RetVal("boolean")
+      }
+    },
+
+    getMetaViewportOverride: {
+      request: {},
+      response: {
+        flag: RetVal("number")
+      }
+    },
+
+    clearMetaViewportOverride: {
+      request: {},
+      response: {
+        valueChanged: RetVal("boolean")
+      }
+    },
+
     setUserAgentOverride: {
       request: {
         flag: Arg(0, "string")