chromeos: Remove AshTestBase::SupportsMultipleDisplays

ash/common/wallpaper/wallpaper_controller_unittest.cc

Index: ash/common/wallpaper/wallpaper_controller_unittest.cc
diff --git a/ash/common/wallpaper/wallpaper_controller_unittest.cc b/ash/common/wallpaper/wallpaper_controller_unittest.cc
index acbb0bf2fd08b9339f3c381fa1f8f95d7363d4ef..b05bf4a462ac68d48fd264d3b71130b67c0dd725 100644
--- a/ash/common/wallpaper/wallpaper_controller_unittest.cc
+++ b/ash/common/wallpaper/wallpaper_controller_unittest.cc
@@ -348,9 +348,6 @@ TEST_F(WallpaperControllerTest, ChangeWallpaperQuick) {
 }
 
 TEST_F(WallpaperControllerTest, ResizeCustomWallpaper) {
-  if (!SupportsMultipleDisplays())
-    return;
-
   UpdateDisplay("320x200");
 
   gfx::ImageSkia image = CreateImage(640, 480, kCustomWallpaperColor);
@@ -388,9 +385,6 @@ TEST_F(WallpaperControllerTest, GetMaxDisplaySize) {
   EXPECT_EQ("1000x300",
             WallpaperController::GetMaxDisplaySizeInNative().ToString());
 
-  if (!SupportsMultipleDisplays())
-    return;
-
   // First display has maximum size.
   UpdateDisplay("400x300,100x100");
   EXPECT_EQ("400x300",