Compute pageScaleFactor on page so that fixed layout page fits width of window.

content/common/content_switches.cc

Index: content/common/content_switches.cc
diff --git a/content/common/content_switches.cc b/content/common/content_switches.cc
index f4d380b2a43b50f873e7690fa253bfc59f098b78..a34f0f05be50e13b6ef977e33d2452ea52be909e 100644
--- a/content/common/content_switches.cc
+++ b/content/common/content_switches.cc
@@ -165,6 +165,10 @@ const char kEnableBenchmarking[]            = "enable-benchmarking";
 // Enables device motion events.
 const char kEnableDeviceMotion[]            = "enable-device-motion";
 
+// By default, a page is laid out to fill the entire width of the window.
+// This flag fixes the layout of the page to a default of 980px.
+const char kEnableFixedLayout[]             = "enable-fixed-layout";
+
 // Enable the JavaScript Full Screen API.
 const char kEnableFullScreen[]              = "enable-fullscreen";