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

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 98a33088124d0ffc4fd9824d230a3d8d8f7910f1..08a3d56b317f998fffb21860982975d783479c1a 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -222,6 +222,10 @@ const char kDebugEnableFrameToggle[]        = "debug-enable-frame-toggle";
 // Enables support to debug printing subsystem.
 const char kDebugPrint[]                    = "debug-print";
 
+// The default device scale factor to use when computing a non-standard fixed
+// width based on the size of the window.
+const char kDefaultDeviceScaleFactor[]      = "default-device-scale-factor";
+
 // Specifies the URL at which to fetch configuration policy from the device
 // management backend. Specifying this switch turns on managed policy from the
 // device management backend.
@@ -473,6 +477,10 @@ const char kEnableExtensionTimelineApi[]    = "enable-extension-timeline-api";
 // for example page cycler and layout tests. See bug 1157243.
 const char kEnableFileCookies[]             = "enable-file-cookies";
 
+// 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 HTTP pipelining. Attempt to pipeline HTTP connections. Heuristics will
 // try to figure out if pipelining can be used for a given host and request.
 // Without this flag, pipelining will never be used.