Rename GetRootWindow() -> GetPrimaryRootWindow()

ash/wm/video_detector_unittest.cc

Index: ash/wm/video_detector_unittest.cc
diff --git a/ash/wm/video_detector_unittest.cc b/ash/wm/video_detector_unittest.cc
index e1861c7ffe141ce8cbd0dbde9a11484881b16ae4..44c4e27eed7bc5f72afb46372a2a1f199d6fec36 100644
--- a/ash/wm/video_detector_unittest.cc
+++ b/ash/wm/video_detector_unittest.cc
@@ -119,7 +119,7 @@ TEST_F(VideoDetectorTest, WindowNotVisible) {
 
   // Reparent the window to the root to make sure that visibility changes aren't
   // animated.
-  Shell::GetRootWindow()->AddChild(window.get());
+  Shell::GetPrimaryRootWindow()->AddChild(window.get());
 
   // We shouldn't report video that's played in a hidden window.
   window->Hide();
@@ -143,7 +143,7 @@ TEST_F(VideoDetectorTest, WindowNotVisible) {
   observer_->reset_stats();
   AdvanceTime(base::TimeDelta::FromSeconds(2));
   gfx::Rect offscreen_bounds(
-      gfx::Point(Shell::GetRootWindow()->bounds().width(), 0),
+      gfx::Point(Shell::GetPrimaryRootWindow()->bounds().width(), 0),
       window_bounds.size());
   window->SetBounds(offscreen_bounds);
   ASSERT_EQ(offscreen_bounds, window->bounds());