Switch default WM mode to managed

ash/shell_unittest.cc

Index: ash/shell_unittest.cc
diff --git a/ash/shell_unittest.cc b/ash/shell_unittest.cc
index db7afd99e00aa11ab55b153958cfde00529f94e4..1f16bf0aa93b0668914b0facf34889d179a54b8c 100644
--- a/ash/shell_unittest.cc
+++ b/ash/shell_unittest.cc
@@ -288,11 +288,11 @@ TEST_F(ShellTest, IsScreenLocked) {
 }
 
 TEST_F(ShellTest, ComputeWindowMode) {
-  // By default, we use overlapping mode.
+  // By default, we use managed mode.
   Shell* shell = Shell::GetInstance();
   Shell::TestApi test_api(shell);
   CommandLine command_line_blank(CommandLine::NO_PROGRAM);
-  EXPECT_EQ(Shell::MODE_OVERLAPPING,
+  EXPECT_EQ(Shell::MODE_MANAGED,
             test_api.ComputeWindowMode(&command_line_blank));
 
   // Sometimes we force compact mode.
@@ -301,6 +301,14 @@ TEST_F(ShellTest, ComputeWindowMode) {
   EXPECT_EQ(Shell::MODE_COMPACT,
             test_api.ComputeWindowMode(&command_line_force));
 
+  // The user can set overlapping mode.
+  CommandLine command_line_overlapping(CommandLine::NO_PROGRAM);
+  command_line_overlapping.AppendSwitchASCII(
+      switches::kAuraWindowMode,
+      switches::kAuraWindowModeOverlapping);
+  EXPECT_EQ(Shell::MODE_OVERLAPPING,
+            test_api.ComputeWindowMode(&command_line_overlapping));
+
   // The user can set compact mode.
   CommandLine command_line_compact(CommandLine::NO_PROGRAM);
   command_line_compact.AppendSwitchASCII(switches::kAuraWindowMode,