[ios] Add ActivityToMoveTab to window_activities

This CL adds a new NSUserActivity type for moving a tab
to a new window.

This CL is one in a series to add drag and drop functionality
in a multi-window world.

Dragging a tab (which will come in a later CL) to the
edge of the screen in an iPad is a gesture to create
a new window with that tab. A custom NSUserActivity is
required to enable this gesture.

Bug: 1087844
Change-Id: I0462f3074825f682ccc4c1e8345f22e310abdcc5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2236896
Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#778848}

ios/chrome/browser/window_activities/BUILD.gn

@@ -10,7 +10,7 @@ source_set("window_activities") {
   ]
   deps = [
     "//base",
-    "//ios/chrome/browser",
+    "//ios/chrome/browser:chrome_url_constants",
     "//ios/chrome/browser/url_loading",
     "//ios/web/public/navigation",
     "//net",

ios/chrome/browser/window_activities/window_activity_helpers.h

@@ -52,10 +52,17 @@ NSUserActivity* ActivityToLoadURL(WindowActivityOrigin origin,
 // |url|.
 NSUserActivity* ActivityToLoadURL(WindowActivityOrigin origin, const GURL& url);
 
+// Create a new activity that moves a tab either between browsers, or reorders
+// within a browser.
+NSUserActivity* ActivityToMoveTab(NSString* tab_id);
+
 // true if |activity| is one that indicates a URL load (including loading the
 // new tab page in a new tab).
 bool ActivityIsURLLoad(NSUserActivity* activity);
 
+// true if |activity| is one that indicates a tab move.
+bool ActivityIsTabMove(NSUserActivity* activity);
+
 // The URLLoadParams needed to perform the load defined in |activity|, if any.
 // If |activity| is not a URL load activity, the default UrlLoadParams are
 // returned.

ios/chrome/browser/window_activities/window_activity_helpers.mm

@@ -17,12 +17,14 @@
 // Activity types.
 NSString* const kLoadURLActivityType = @"org.chromium.load.url";
 NSString* const kLoadIncognitoURLActivityType = @"org.chromium.load.otr-url";
+NSString* const kMoveTabActivityType = @"org.chromium.move-tab";
 
 // User info keys.
 NSString* const kURLKey = @"LoadParams_URL";
 NSString* const kReferrerURLKey = @"LoadParams_ReferrerURL";
 NSString* const kReferrerPolicyKey = @"LoadParams_ReferrerPolicy";
 NSString* const kOriginKey = @"LoadParams_Origin";
+NSString* const kTabIdentifierKey = @"TabIdentifier";
 
 namespace {
 
@@ -74,11 +76,22 @@ NSUserActivity* ActivityToLoadURL(WindowActivityOrigin origin,
   return activity;
 }
 
+NSUserActivity* ActivityToMoveTab(NSString* tab_id) {
+  NSUserActivity* activity =
+      [[NSUserActivity alloc] initWithActivityType:kMoveTabActivityType];
+  [activity addUserInfoEntriesFromDictionary:@{kTabIdentifierKey : tab_id}];
+  return activity;
+}
+
 bool ActivityIsURLLoad(NSUserActivity* activity) {
   return [activity.activityType isEqualToString:kLoadURLActivityType] ||
          [activity.activityType isEqualToString:kLoadIncognitoURLActivityType];
 }
 
+bool ActivityIsTabMove(NSUserActivity* activity) {
+  return [activity.activityType isEqualToString:kMoveTabActivityType];
+}
+
 UrlLoadParams LoadParamsFromActivity(NSUserActivity* activity) {
   if (!ActivityIsURLLoad(activity))
     return UrlLoadParams();