Support DirectWrite with sandbox on

content/common/sandbox_win.cc

Index: content/common/sandbox_win.cc
diff --git a/content/common/sandbox_win.cc b/content/common/sandbox_win.cc
index aea586054e51329e97627abc203ac3cfdb7f2b06..f8ce64292ff28e1a9bbaa166b5433a9036b68ca4 100644
--- a/content/common/sandbox_win.cc
+++ b/content/common/sandbox_win.cc
@@ -571,6 +571,16 @@ bool InitTargetServices(sandbox::TargetServices* target_services) {
   return sandbox::SBOX_ALL_OK == result;
 }
 
+bool ShouldUseDirectWrite() {
+  // If the flag is currently on, and we're on Win7 or above, we enable
+  // DirectWrite. Skia does not require the additions to DirectWrite
+  // in QFE 2670838, so a Win7 check is sufficient. We don't not currently
+  // attempt to support Vista, where SP2 and the Platform Update are required.
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  return command_line.HasSwitch(switches::kEnableDirectWrite) &&
+         base::win::GetVersion() >= base::win::VERSION_WIN7;
+}
+
 base::ProcessHandle StartSandboxedProcess(
     SandboxedProcessLauncherDelegate* delegate,
     CommandLine* cmd_line) {
@@ -637,7 +647,19 @@ base::ProcessHandle StartSandboxedProcess(
   if (!disable_default_policy && !AddPolicyForSandboxedProcess(policy))
     return 0;
 
-  if (type_str != switches::kRendererProcess) {
+  if (type_str == switches::kRendererProcess) {
+    if (ShouldUseDirectWrite()) {
+      AddDirectory(base::DIR_WINDOWS_FONTS,
+                  NULL,
+                  true,
+                  sandbox::TargetPolicy::FILES_ALLOW_READONLY,
+                  policy);
+      // We do not automatically propagate this from the browser command line,
+      // and instead only add it when we're actually setting up the sandbox to
+      // work with DirectWrite.
+      cmd_line->AppendSwitch(switches::kEnableDirectWrite);
+    }
+  } else {
     // Hack for Google Desktop crash. Trick GD into not injecting its DLL into
     // this subprocess. See
     // http://code.google.com/p/chromium/issues/detail?id=25580