Mourners stand at attention as the bodies of two fallen NYPD police officers are transported from Woodhull Medical Center, Saturday, December 20, 2014, in New York. An armed man walked up to two New York Police Department officers sitting inside a patrol car and opened fire Saturday afternoon, killing one and critically wounding a second before running into a nearby subway station and committing suicide, police said. (Photo by John Minchillo/AP Photo)

New York City Police officers pause as they visit a makeshift memorial at the site where two of their fellow police officers were fatally shot in the Brooklyn borough of New York, December 23, 2014. NYPD officers, Wenjian Liu and Rafael Ramos were shot and killed as they sat in a marked squad car in Brooklyn on Saturday afternoon, New York Police Commissioner William Bratton said. The suspect in the shooting then shot and killed himself, according to Bratton. (Photo by Mike Segar/Reuters)

New York Police Department Lt. Tanisha Gurley visits a makeshift memorial, Tuesday, December 23, 2014, near the site where NYPD officers Rafael Ramos and Wenjian Liu were murdered in the Brooklyn borough of New York. Police say Ismaaiyl Brinsley ambushed the two officers in their patrol car in broad daylight Saturday, fatally shooting them before killing himself inside a subway station. (Photo by Craig Ruttle/AP Photo)

A woman closes her eyes and leans into the wind during the evening of the Winter Solstice at the Castlerigg Stone circle on December 21, 2014 in Keswick, England. The circle dates back over 4,000 years to neolithic times and is a popular meeting place for people from all over Britain who come to celebrate both the winter and summer solstices with the beautiful Cumbrian fells as a backdrop. (Photo by Ian Forsyth/Getty Images)

St Paul's Choristers rehearse in the cathedral in London, Monday, December 22, 2014, preparing for their busiest days of the year. (Photo by Kirsty Wigglesworth/AP Photo)

British travelers and twin sisters Dabriella, left, and Aprilla Quayle, right, ride the waves while celebrating Christmas Day at Bondi Beach in Sydney, Thursday, December 25, 2014. (Photo by Rick Rycroft/AP Photo)

A large balloon of a face of “ojisan”, a middle aged man, floats in the sky above the grounds of Nishiki elementary school in Utsunomiya in Tochigi prefecture, 100km north of Tokyo on December 21, 2014. Members of art group “Me”, meaning “eye” in Japanese and the Utsunomiya Museum of Art launched an art installation “The Day an Ojisan's Face Floated in the Sky”, a 15-meter by 10-meter face balloon of the depicted man, who was auditioned in the city, looking down on his home town from the sky. (Photo by Yoshikazu Tsuno/AFP Photo)

This picture taken on December 24, 2014 shows university students wearing traditional Chinese outfits holding banners reading “Resist Christmas, Chinese people should not celebrate foreign festivals” in Changsha, central China's Hunan province during an anti-Christmas street protest. A Chinese city has banned schools from holding Christmas events, state media reported on December 25, highlighting official suspicions about the increasingly popular festival because of its foreign origins. (Photo by AFP Photo)

Re-enactors, from various living history groups, are dressed in World War I British and German uniforms as they kick around a soccer ball during a re-enactment of the 1914 Christmas Truce in Ploegsteert, Belgium on Saturday, December 20, 2014. During that first Christmas Day in World War I, something magical happened. Soldiers who had been killing each other by the tens of thousands for months climbed out of their muddy trenches to seek a shred of humanity amid the horrors of war. Hands reached out across the narrow divide, presents were exchanged, and in Flanders Fields a century ago, a spontaneous Christmas truce briefly lifted the human spirit. (Photo by Virginia Mayo/AP Photo)

An Israeli soldier walks with a detained Palestinian teenager who military said illegally crossed into Israel near the Israel Gaza border, Wednesday, December 24, 2014. The Israeli military said it deployed tank fire and an airstrike on targets in Gaza after its troops came under attack by Palestinian snipers as they were on patrol on the Israeli side of the border. (Photo by Tsafrir Abayov/AP Photo)

This picture taken on December 24, 2014 shows Xu Zhiyun posing with a mini car he assembled in his community in Shanghai. 60-year-old Xu Zhiyun spent two years making the car which measures only 60cm long, 35cm wide, 40cm high, travels at 20 km per hour and cost 1500 yuan, local media reported. (Photo by AFP Photo)

Christians attend the mass service at a flooded church in Bandung, in western Java island, on December 25, 2014. Millions of Christians in Indonesia celebrate the Christmas eve in the most populous Muslim country. (Photo by Timur Matahari/AFP Photo)

Police try to control a crowd Wednesday, December 24, 2014, on the lot of a gas station following a shooting Tuesday in Berkeley, Mo. St. Louis County police say a man who pulled a gun and pointed it at an officer has been killed. (Photo by David Carson/AP Photo/St. Louis Post-Dispatch)

A Filipino boy walks past Christmas decorations for sale in Manila, Philippines on Monday, December 22, 2014. Christmas is one of the most important holidays in this predominantly Roman Catholic nation. (Photo by Aaron Favila/AP Photo)

A woman stands on the street in downtown Havana December 19, 2014. (Photo by Alexandre Meneghini/Reuters)

People dressed in illuminated angel costumes parade to mark Christmas Day in central Moscow, Russia, on Thursday, December 25, 2014. (Photo by Pavel Golovkin/AP Photo)

People dressed in illuminated angel costumes parade to mark Christmas Day in central Moscow, Russia, on Thursday, December 25, 2014. (Photo by Pavel Golovkin/AP Photo)

A man walks past sand-made statue “Snowman” standing three metres high at Hilton Beach in Tel Aviv, Israel, December 24, 2014. (Photo by Daniel Bar On/EPA)

A fighting rooster waits in the sun for his next fight, in Havana, Cuba, Monday, December 22, 2014. The restoration of diplomatic ties between Cuba and the United States has unleashed expectations of even more momentous changes on an island that often seems frozen in a past of classic cars and crumbling buildings. (Photo by Ramon Espinosa/AP Photo)

A woman offers biscuits to honor guard soldiers before a commemoration at the Revolution Heroes Cemetery in Bucharest ,Romania, Sunday, December 21, 2014. The anti-communist uprising, which left more than thousands dead, and ended the rule of dictator Nicolae Ceausescu, who was executed, started in the western Romanian town of Timisoara on Dec. 16, 1989 and in Bucharest, Romania's capital on Dec. 21, 1989. (Photo by Vadim Ghirda/AP Photo)

A Christmas tree made of colorful illuminated balls is seen in Gorky park in Moscow, Russia, as preparation for the holiday season on 21 December 2014. (Photo by Yuri Kochetkov/EPA)

A FEMEN activist is arrested by Vatican police as she stages a protest inside the Vatican crib in St.Peter's square on December 25, 2014, at the Vatican. (Photo by Vincenzo Livieri/AFP Photo)

A FEMEN activist is arrested by Vatican police as she stages a protest inside the Vatican crib in St.Peter's square on December 25, 2014, at the Vatican. (Photo by Vincenzo Livieri/AFP Photo)

Danya Richards, 15, heads backstage to wait for her cue during a performance of “The Nutcracker” by the Fredericksburg Ballet Centre at James Monroe High School on Sunday December 21, 2014 in Fredericksburg, VA. This was the final performance of “The Nutcracker” by the Fredericksburg Ballet Centre for the holiday season. (Photo by Matt McClain/The Washington Post)

A child (R) walks past a three-dimensional art painting featuring Santa Claus, entitled “Santa's Christmas Gift”, presented by the interactive art museum “Art in Island” in Manila, as another (L) poses for a photo on December 24, 2014. The Philippines is the largest Christian country in Asia and has one of the longest Christmas seasons in the world, lasting from December 16 to January 6. (Photo by Noel Celis/AFP Photo)

Andre Icard and Rene Clavel, confectioners working at “Clavel”, work on the glazing of pinapples during the preparation of candied fruits on December 22, 2014 in Carpentras. The candied fruit is part of the 13 traditional deserts in the Provence region, south eatern France. (Photo by Boris Horvat/AFP Photo)

Pakistani boys enjoy jumping on a trampoline, at a makeshift entertainment park set up in a Christian neighborhood for Christmas holiday, in Islamabad, Pakistan, Tuesday, December 23, 2014. (Photo by Muhammed Muheisen/AP Photo)

This photograph taken on December 20, 2014 shows female Pakistani police commandos during an exercise at a police training centre in Nowshera, a district in the Khyber Pakhtunkhwa Province. The army has been waging a major offensive against longstanding Taliban and other militant strongholds in the restive tribal areas on the Afghan border for the last six months. But a series of fresh strikes after the December 16 Peshawar attack, which left 149 people dead – most of them children, suggest the military is stepping up its campaign. As the Peshawar tragedy unfolded, army chief General Raheel Sharif said the attack had renewed the forces' determination to push for the militants' “final elimination”. (Photo by A. Majeed/AFP Photo)

This photo provided by Columbia Pictures – Sony shows, from left, Diana Bang, as Sook, Seth Rogen, as Aaron, and James Franco, as Dave, in Columbia Pictures’ “The Interview”. When a group claiming credit for the hacking of Sony Pictures Entertainment threated violence against theaters showing “The Interview” earlier this week, Sony Pictures and several national theater chains surrendered to the hackers and North Korea by pulling the movie ahead of its planned Christmas release. (Photo by Ed Araquel/AP Photo/Columbia Pictures – Sony)

Sri Lankan President Mahinda Rajapaksa, center in front row, watches traditional dancers perform during the launch of his election manifesto in Colombo, Sri Lanka, Tuesday, December 23, 2014. Rajapaksa will face his former health minister Maithripala Sirisena in the January 8 presidential elections. (Photo by Eranga Jayawardena/AP Photo)

People drink coffee at a street cafe in downtown Kiev, Ukraine, Wednesday, December 24, 2014. Ukrainians enjoy an unusually warm weather a week before the New Year. (Photo by Efrem Lukatsky/AP Photo)

Street performer Bold Yamada shakes hands with a child at a park in Tokyo, Monday, December 22, 2014. (Photo by Shizuo Kambayashi/AP Photo)

Visitors are silhouetted with decorated lights on trees to celebrate the upcoming Christmas and New Year at Garden of Morning Calm in Gapyeong, South Korea, Monday, December 22, 2014. Christmas is one of the biggest holidays in South Korea. (Photo by Ahn Young-joon/AP Photo)

In this Monday, December 22, 2014, photo taken with a slow shutter, the Denver City/County building is illuminated by the traditional holiday light display, in Denver. The holiday lights will burn each evening through New Year's Eve and then resume for the annual run of the National Western Stock Show and Rodeo. (Photo by David Zalubowski/AP Photo)