Give SxS distribution its own registration GUIDs.

chrome/browser/ui/webui/options/browser_options_handler.cc

Index: chrome/browser/ui/webui/options/browser_options_handler.cc
diff --git a/chrome/browser/ui/webui/options/browser_options_handler.cc b/chrome/browser/ui/webui/options/browser_options_handler.cc
index 1cde684e37915fcc7e10e7ccf044b49b42428b57..e93eaf450a697e1b56abf305ffde3fe5faf2d9c1 100644
--- a/chrome/browser/ui/webui/options/browser_options_handler.cc
+++ b/chrome/browser/ui/webui/options/browser_options_handler.cc
@@ -107,7 +107,9 @@
 #endif  // defined(OS_CHROMEOS)
 
 #if defined(OS_WIN)
+#include <windows.h>
 #include "chrome/installer/util/auto_launch_util.h"
+#include "chrome/installer/util/browser_distribution.h"
 #endif  // defined(OS_WIN)
 
 using content::BrowserContext;
@@ -748,6 +750,15 @@ void BrowserOptionsHandler::InitializeHandler() {
 
 void BrowserOptionsHandler::InitializePage() {
   page_initialized_ = true;
+#if defined(OS_WIN)
+  // On Windows, allow a magic key combination to enable SxS distributions to
+  // be set as the default browser.  This allows testing scenarios which were
+  // previously not possible on Windows 8.
+  if (GetAsyncKeyState(VK_SHIFT) && GetAsyncKeyState(VK_F12)) {
+    BrowserDistribution* dist = BrowserDistribution::GetDistribution();
+    dist->DebugEnableSetAsDefault();
+  }
+#endif
 
   OnTemplateURLServiceChanged();