Enable pinch-to-zoom on Windows 8 by default

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 9eba10011c861162cdcc9ce5000ee3e6f5d14664..dafa082439bee5ed6bc898d8e9b66b839e220e0b 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -151,6 +151,7 @@
 #include "webkit/common/webpreferences.h"
 
 #if defined(OS_WIN)
+#include "base/win/windows_version.h"
 #include "chrome/browser/chrome_browser_main_win.h"
 #include "sandbox/win/src/sandbox_policy.h"
 #elif defined(OS_MACOSX)
@@ -1449,6 +1450,11 @@ void ChromeContentBrowserClient::AppendExtraCommandLineSwitches(
           chromeos::switches::kLoginProfile, login_profile);
 #endif
 
+#if defined(OS_WIN)
+  if (base::win::GetVersion() >= base::win::VERSION_WIN8)
+    command_line->AppendSwitch(switches::kEnablePinch);
+#endif
+
 #if defined(ENABLE_WEBRTC)
     if (VersionInfo::GetChannel() <= VersionInfo::CHANNEL_DEV) {
       static const char* const kWebRtcDevSwitchNames[] = {