src/crypto should build on the x86_64 architecture.

crypto/mock_keychain_mac.cc

Index: crypto/mock_keychain_mac.cc
===================================================================
--- crypto/mock_keychain_mac.cc	(revision 145645)
+++ crypto/mock_keychain_mac.cc	(working copy)
@@ -175,7 +175,7 @@
     UInt32* length,
     void** outData) const {
   DCHECK(itemRef);
-  unsigned int key = reinterpret_cast<unsigned int>(itemRef) - 1;
+  uintptr_t key = reinterpret_cast<uintptr_t>(itemRef) - 1;
   if (keychain_attr_list_.find(key) == keychain_attr_list_.end())
     return errSecInvalidItemRef;
 
@@ -204,7 +204,7 @@
     return errSecAuthFailed;
   }
 
-  unsigned int key = reinterpret_cast<unsigned int>(itemRef) - 1;
+  uintptr_t key = reinterpret_cast<uintptr_t>(itemRef) - 1;
   if (keychain_attr_list_.find(key) == keychain_attr_list_.end())
     return errSecInvalidItemRef;
 
@@ -232,7 +232,7 @@
 }
 
 OSStatus MockKeychain::ItemDelete(SecKeychainItemRef itemRef) const {
-  unsigned int key = reinterpret_cast<unsigned int>(itemRef) - 1;
+  uintptr_t key = reinterpret_cast<uintptr_t>(itemRef) - 1;
 
   for (unsigned int i = 0; i < keychain_attr_list_[key].count; ++i) {
     if (keychain_attr_list_[key].attr[i].data)
@@ -483,7 +483,7 @@
   if (!ref)
     return;
 
-  if (reinterpret_cast<int>(ref) == kDummySearchRef) {
+  if (reinterpret_cast<uintptr_t>(ref) == kDummySearchRef) {
     --search_copy_count_;
   } else {
     --keychain_item_copy_count_;