Put app shim IPC socket in a temporary directory. (Mac)

chrome/common/mac/app_mode_common.mm

Index: chrome/common/mac/app_mode_common.mm
diff --git a/chrome/common/mac/app_mode_common.mm b/chrome/common/mac/app_mode_common.mm
index 317dec3b6331e32aa8ae332f02d4c4d9b74708f8..0af762c67daab3b56d9b6966109d39f711e2a3e1 100644
--- a/chrome/common/mac/app_mode_common.mm
+++ b/chrome/common/mac/app_mode_common.mm
@@ -4,6 +4,10 @@
 
 #include "chrome/common/mac/app_mode_common.h"
 
+#include "base/base64.h"
+#include "base/sha1.h"
+#include "base/strings/string_util.h"
+
 namespace app_mode {
 
 const char kAppShimSocketName[] = "App Shim Socket";
@@ -40,4 +44,19 @@ ChromeAppModeInfo::ChromeAppModeInfo()
 ChromeAppModeInfo::~ChromeAppModeInfo() {
 }
 
+base::FilePath GetShortSocketPath(const base::FilePath& user_data_dir) {
+  std::string udd_hash;
+  if (base::Base64Encode(base::SHA1HashString(user_data_dir.value()),
+                         &udd_hash)) {
+    ReplaceChars(udd_hash, "/", "_", &udd_hash);
+    DCHECK_EQ(28u, udd_hash.length());
+    return base::FilePath("/tmp")
+        .Append("chrome-" + udd_hash)
+        .Append(kAppShimSocketName);
+  }
+
+  NOTREACHED();
+  return base::FilePath();
+}
+
 }  // namespace app_mode