Remove Windows mock theme engine code.

content/shell/renderer/test_runner/TestInterfaces.cpp

Index: content/shell/renderer/test_runner/TestInterfaces.cpp
diff --git a/content/shell/renderer/test_runner/TestInterfaces.cpp b/content/shell/renderer/test_runner/TestInterfaces.cpp
index 5ce33dab784379a44510881c616438332ad8ed70..fda4c2c197e1409de0e00faa3a8365b0b11dc3c2 100644
--- a/content/shell/renderer/test_runner/TestInterfaces.cpp
+++ b/content/shell/renderer/test_runner/TestInterfaces.cpp
@@ -176,21 +176,14 @@ WebThemeEngine* TestInterfaces::themeEngine()
 {
     if (!m_testRunner->useMockTheme())
         return 0;
-#if defined(USE_DEFAULT_RENDER_THEME) || !(defined(WIN32) || defined(__APPLE__) || defined(ANDROID))
-    if (!m_themeEngine.get())
-        m_themeEngine.reset(new WebTestThemeEngineMock());
-    return m_themeEngine.get();
-#elif defined(WIN32)
-    if (!m_themeEngine.get())
-        m_themeEngine.reset(new WebTestThemeEngineWin());
-    return m_themeEngine.get();
-#elif defined(__APPLE__)
+#if defined(__APPLE__)
     if (!m_themeEngine.get())
         m_themeEngine.reset(new WebTestThemeEngineMac());
-    return m_themeEngine.get();
 #else
-    return 0;
+    if (!m_themeEngine.get())
+        m_themeEngine.reset(new WebTestThemeEngineMock());
 #endif
+    return m_themeEngine.get();
 }
 
 }