Remove deprecated mac screencapture code.

We don't support pre-lion, so all this screencapture code is unnecessary.
This also enables us to delete some code from rtc_base/macutils

Bug: webrtc:6424
Change-Id: I4ef068e8d7b48de9370feee51399033a4d1ae1c3
Reviewed-on: https://webrtc-review.googlesource.com/3420
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20104}

rtc_base/macutils.h

@@ -15,36 +15,8 @@
 #include <string>
 
 namespace rtc {
-
-///////////////////////////////////////////////////////////////////////////////
-
-// Note that some of these functions work for both iOS and Mac OS X.  The ones
-// that are specific to Mac are #ifdef'ed as such.
-
 bool ToUtf8(const CFStringRef str16, std::string* str8);
 bool ToUtf16(const std::string& str8, CFStringRef* str16);
-
-#if defined(WEBRTC_MAC) && !defined(WEBRTC_IOS)
-void DecodeFourChar(UInt32 fc, std::string* out);
-
-enum MacOSVersionName {
-  kMacOSUnknown,       // ???
-  kMacOSOlder,         // 10.2-
-  kMacOSPanther,       // 10.3
-  kMacOSTiger,         // 10.4
-  kMacOSLeopard,       // 10.5
-  kMacOSSnowLeopard,   // 10.6
-  kMacOSLion,          // 10.7
-  kMacOSMountainLion,  // 10.8
-  kMacOSMavericks,     // 10.9
-  kMacOSNewer,         // 10.10+
-};
-
-MacOSVersionName GetOSVersionName();
-#endif
-
-///////////////////////////////////////////////////////////////////////////////
-
 }  // namespace rtc
 
 #endif  // RTC_BASE_MACUTILS_H_