Revert of Remove all reference to carbon api (patchset #2 id:20001 of https://codereview.webrtc.org/2299633002/ )

Reason for revert:
Breaks chromium build

Original issue's description:
> Remove all reference to carbon api
>
> BUG=webrtc:6282
>
> Committed: https://crrev.com/dbd8b6bec4143c940b2f2ca8cd85c25d17327964
> Cr-Commit-Position: refs/heads/master@{#14080}

TBR=magjed@webrtc.org,mflodman@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6282

Review-Url: https://codereview.webrtc.org/2316563002
Cr-Commit-Position: refs/heads/master@{#14081}
diff --git a/webrtc/base/unixfilesystem.cc b/webrtc/base/unixfilesystem.cc
index 4dea6b8..b474324 100644
--- a/webrtc/base/unixfilesystem.cc
+++ b/webrtc/base/unixfilesystem.cc
@@ -17,7 +17,7 @@
 #include <unistd.h>
 
 #if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)
-#include <CoreFoundation/CoreFoundation.h>
+#include <Carbon/Carbon.h>
 #include <IOKit/IOCFBundle.h>
 #include <sys/statvfs.h>
 #include "webrtc/base/macutils.h"
@@ -50,13 +50,13 @@
 #include "webrtc/base/stream.h"
 #include "webrtc/base/stringutils.h"
 
-#if defined(WEBRTC_MAC)
-// Defined in applefilesystem.mm.  No header file to discourage use
+#if defined(WEBRTC_IOS)
+// Defined in iosfilesystem.mm.  No header file to discourage use
 // elsewhere; other places should use GetApp{Data,Temp}Folder() in
 // this file.  Don't copy/paste.  I mean it.
-char* AppleDataDirectory();
-char* AppleTempDirectory();
-void AppleAppName(rtc::Pathname* path);
+char* IOSDataDirectory();
+char* IOSTempDirectory();
+void IOSAppName(rtc::Pathname* path);
 #endif
 
 namespace rtc {
@@ -81,9 +81,9 @@
 UnixFilesystem::UnixFilesystem() {
 #if defined(WEBRTC_IOS)
   if (!provided_app_data_folder_)
-    provided_app_data_folder_ = AppleDataDirectory();
+    provided_app_data_folder_ = IOSDataDirectory();
   if (!provided_app_temp_folder_)
-    provided_app_temp_folder_ = AppleTempDirectory();
+    provided_app_temp_folder_ = IOSTempDirectory();
 #endif
 }
 
@@ -357,10 +357,24 @@
 }
 
 bool UnixFilesystem::GetAppPathname(Pathname* path) {
-#if defined(__native_client__)
+#if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)
+  ProcessSerialNumber psn = { 0, kCurrentProcess };
+  CFDictionaryRef procinfo = ProcessInformationCopyDictionary(&psn,
+      kProcessDictionaryIncludeAllInformationMask);
+  if (NULL == procinfo)
+    return false;
+  CFStringRef cfpath = (CFStringRef) CFDictionaryGetValue(procinfo,
+      kIOBundleExecutableKey);
+  std::string path8;
+  bool success = ToUtf8(cfpath, &path8);
+  CFRelease(procinfo);
+  if (success)
+    path->SetPathname(path8);
+  return success;
+#elif defined(__native_client__)
   return false;
-#elif defined(WEBRTC_MAC)
-  AppleAppName(path);
+#elif WEBRTC_IOS
+  IOSAppName(path);
   return true;
 #else  // WEBRTC_MAC && !defined(WEBRTC_IOS)
   char buffer[PATH_MAX + 2];