DevTools: explicitly control support for viewport meta tag so that desktop emulation was possible

LayoutTests/inspector/styles/override-and-disable.html

Index: LayoutTests/inspector/styles/override-and-disable.html
diff --git a/LayoutTests/inspector/styles/override-and-disable.html b/LayoutTests/inspector/styles/override-and-disable.html
index 3668086954bc061bec62284e31990fc1cc5df208..05d5f38be8f259e8431fe8307014c593d2bbb890 100644
--- a/LayoutTests/inspector/styles/override-and-disable.html
+++ b/LayoutTests/inspector/styles/override-and-disable.html
@@ -106,7 +106,7 @@ function test()
         }
         
         var enabled = width > 0 && height > 0;
-        PageAgent.setDeviceMetricsOverride(width, height, 1, true, callback);
+        PageAgent.setDeviceMetricsOverride(width, height, 1, false, true, callback);
         overridesEnabled = enabled;
     }