Revert of Mojo: Armed Watchers

ios/web/webui/mojo_facade_unittest.mm

Index: ios/web/webui/mojo_facade_unittest.mm
diff --git a/ios/web/webui/mojo_facade_unittest.mm b/ios/web/webui/mojo_facade_unittest.mm
index cf7e5125bff2e7623299bd2eba2ac4a90990a2d9..542124c4a20567327c6e0454f454513381994130 100644
--- a/ios/web/webui/mojo_facade_unittest.mm
+++ b/ios/web/webui/mojo_facade_unittest.mm
@@ -199,18 +199,6 @@
                                  callback_id, MOJO_RESULT_OK];
   [[[evaluator() expect] andDo:^(NSInvocation*) {
     callback_received = true;
-
-    // Cancel the watch immediately to ensure there are no additional
-    // notifications.
-    NSDictionary* cancel_watch = @{
-      @"name" : @"support.cancelWatch",
-      @"args" : @{
-        @"watchId" : @(watch_id),
-      },
-    };
-    std::string result_as_string =
-        facade()->HandleMojoMessage(GetJson(cancel_watch));
-    EXPECT_TRUE(result_as_string.empty());
   }] executeJavaScript:expected_script completionHandler:nil];
 
   // Write to the other end of the pipe.