Revert of Remove enable_topchrome_md build flag

ui/base/material_design/material_design_controller_unittest.cc

Index: ui/base/material_design/material_design_controller_unittest.cc
diff --git a/ui/base/material_design/material_design_controller_unittest.cc b/ui/base/material_design/material_design_controller_unittest.cc
index b4d913d6760e23fdf46c1bc895fd563104bb9e8d..b86820d89c7174d03ff858e852e7435ed45a9d04 100644
--- a/ui/base/material_design/material_design_controller_unittest.cc
+++ b/ui/base/material_design/material_design_controller_unittest.cc
@@ -48,8 +48,10 @@
 
 void MaterialDesignControllerTest::SetCommandLineSwitch(
     const std::string& value_string) {
+#if defined(ENABLE_TOPCHROME_MD)
   base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
       switches::kTopChromeMD, value_string);
+#endif  // defined(ENABLE_TOPCHROME_MD)
 }
 
 class MaterialDesignControllerTestMaterial :
@@ -95,6 +97,18 @@
  private:
   DISALLOW_COPY_AND_ASSIGN(MaterialDesignControllerTestInvalid);
 };
+
+#if !defined(ENABLE_TOPCHROME_MD)
+
+// Verify the Mode maps to Mode::NON_MATERIAL when the compile time flag is not
+// defined.
+TEST_F(MaterialDesignControllerTest,
+       NonMaterialModeWhenCompileTimeFlagDisabled) {
+  EXPECT_EQ(MaterialDesignController::Mode::NON_MATERIAL,
+            MaterialDesignController::GetMode());
+}
+
+#else
 
 // Verify command line value "material" maps to Mode::MATERIAL when the compile
 // time flag is defined.
@@ -144,5 +158,7 @@
   EXPECT_TRUE(MaterialDesignController::IsModeMaterial());
 }
 
+#endif  // !defined(ENABLE_TOPCHROME_MD)
+
 }  // namespace
 }  // namespace ui