Revert "Fix deprecatation warning when building for recent SDKs on iOS/OS X."

This reverts CL https://codereview.chromium.org/1563223004/
This reverts commit 7cc0d8562bf8b20b88cc941ba72593cb7230ecf6.

CL 1563223004 introduces two bugs on iOS.
- Encoding the minidump name with extra percent causing crash server to fail
  processing the file.
- Using a released pointer causing random crashes on upload. The
  data, resp, err pointers returned in the NSURLSession completion
  handler is released at the end of the block. When used later (to get
  the crash ID), it causes a crash.

BUG=569158
R=blundell@chromium.org, mark@chromium.org

Review URL: https://codereview.chromium.org/1619603002 .

Patch from Olivier Robin <olivierrobin@chromium.org>.

src/client/mac/handler/minidump_generator.cc

@@ -154,9 +154,9 @@ void MinidumpGenerator::GatherSystemInformation() {
   if (!data) {
     return;
   }
-  CFDictionaryRef list =
-      static_cast<CFDictionaryRef>(CFPropertyListCreateWithData(
-          NULL, data, kCFPropertyListImmutable, NULL, NULL));
+  CFDictionaryRef list = static_cast<CFDictionaryRef>
+    (CFPropertyListCreateFromXMLData(NULL, data, kCFPropertyListImmutable,
+                                     NULL));
   CFRelease(data);
   if (!list) {
     return;