Question: Which Canadian singer was originally featured on the song "Bankroll" by American DJ Diplo?

Context paragraphs:
Skrillex and Diplo Present Jack Ü: Skrillex and Diplo Present Jack Ü is the debut studio album by American DJ duo Jack Ü, individually known as Skrillex and Diplo.  It was released on February 27, 2015 by OWSLA and Mad Decent, Skrillex and Diplo's respective labels.  The album features collaborations with a range of artists including Kiesza, AlunaGeorge, 2 Chainz, Missy Elliott and Justin Bieber.  It also features the Trinidadian soca artist Bunji Garlin.  The album produced the internationally successful single "Where Are Ü Now" featuring Justin Bieber.

Piracy Funds Terrorism: Piracy Funds Terrorism Volume 1, usually referred to simply as Piracy Funds Terrorism, is a mixtape produced by British recording artist M.I.A. and American DJ Diplo featuring vocal tracks intended for M.I.A.'s debut album "Arular" mashed up with samples of other recordings.  The mixtape was produced by the two artists at Diplo's home studio in Philadelphia, Pennsylvania.  It was not officially released, but was distributed at M.I.A.'s live shows and via the internet to promote the release of her much-delayed debut album.  Despite its unofficial status, the mixtape received general acclaim among critics.  Several music publications included the mixtape in their listings of the best albums of 2004.

Diplo discography: American DJ, producer and singer Diplo has released one studio album, six EPs, five compilations, four mixtapes, one live album and a series of singles, music videos and other appearances.  His alias, short for "Diplodocus", derives from his childhood fascination with dinosaurs.  During his rise to fame, Diplo worked with British musician M.I.A., an artist who is credited with giving him exposure in his early career.  Since then, Diplo has worked on production and mixtape projects with many other pop artists, such as Die Antwoord, Britney Spears, Madonna, Shakira, Beyoncé, No Doubt, Justin Bieber, Usher, Snoop Dogg, Chris Brown, CL, and G-Dragon.  As an artist, Diplo, combined with his other collaborations Major Lazer and Jack Ü, two electronic groups.

Take Ü There: "Take Ü There" is the debut collaboration single by American EDM DJ duo Skrillex and Diplo together as Jack Ü, written and performed by the duo and Canadian singer Kiesza, and produced by the duo.  It serves as the lead single from Jack Ü's debut studio album "Skrillex and Diplo Present Jack Ü", and was released on October 4, 2014 through Skrillex's OWSLA and Diplo's Mad Decent.  It peaked at number 63 on the UK Singles Chart.  The song was remixed by producer Kayzo.

Bankroll (song): "Bankroll" is a song by American DJ Diplo.  It features rappers Rich Chigga, Rich the Kid and Young Thug.  Originally, Justin Bieber was featured on the song, but due to Bieber already having exclusives with DJ Khaled ("I'm the One") and David Guetta ("2U") at around the same time as Diplo released "Bankroll", Diplo was forced to remove the original from his SoundCloud account.  Diplo replaced Bieber's verse with a verse from Rich Chigga.

Elliphant: Ellinor Miranda Salome Olovsdotter (born 8 October 1985), known professionally as Elliphant, is a Swedish singer, songwriter and rapper.  Elliphant's sound was initially created together with the Swedish production duo Jungle, which consists of Tim Deneve and Ted Krotkiewski.  The music they created together caught the attention of TEN Music Group, to which Elliphant signed in 2011.  Elliphant also supported Major Lazer, the side project of American producer and DJ Diplo, on their 2015 European tour.

C'mon (Catch 'Em by Surprise): "C'mon (Catch 'em by Surprise)" is a song by Dutch DJ Tiësto and American DJ Diplo.  It features vocals by American rapper Busta Rhymes.  It was released on 14 January 2011 in the Netherlands, United Kingdom and Finland.  The single was released in the United States on iTunes 24 January 2011.

I'm the One (DJ Khaled song): "I'm the One" is a song written and performed by American musician DJ Khaled; Canadian singer Justin Bieber; and American rappers Quavo, Chance the Rapper and Lil Wayne.  The song was released on April 28, 2017, by We the Best and Epic Records as the second single from Khaled's tenth studio album, "Grateful".

Pon de Floor: "Pon de Floor" is a song by Major Lazer, a collaborative musical project consisting of the American DJ Diplo and the British DJ Switch.  The single was released in 2009 by Mad Decent and Downtown Records as the second single from Major Lazer's first studio album, "Guns Don't Kill People... Lazers Do" (2009).  The duo wrote the song and produced it with Afrojack with drums by Nebat Drums  and vocals by Vybz Kartel.  "Pon de Floor" is a dancehall and baile funk song and was positively received by music critics.  It appeared on the charts in the United Kingdom in 2010, where it reached number 125.  Eric Wareheim directed the music video for "Pon de Floor", which shows people dry humping, and incorporates daggering choreography.

Top Ranking: A Diplo Dub: Top Ranking: A Diplo Dub is a mixtape by American artist Santigold (then going by "Santogold") and Philadelphia-based DJ Diplo, released on July 15, 2008.

Supporting paragraphs: Bankroll (song) I'm the One (DJ Khaled song)
Answer: Justin Bieber