Migrate to OS_MAC and OS_APPLE in ppapi

Bug: 1105907
Change-Id: Ib35f5ba08945da527a2a9374b9f11bc221bf393e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2325099Reviewed-by: Raymes Khoury <raymes@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792990}

ppapi/proxy/flash_resource.cc

@@ -136,7 +136,7 @@ double FlashResource::GetLocalTimeZoneOffset(PP_Instance instance,
   // require filesystem access prohibited by the sandbox.
   // TODO(shess): Figure out why OSX needs the access, the sandbox warmup should
   // handle it.  http://crbug.com/149006
-#if defined(OS_LINUX) || defined(OS_MACOSX)
+#if defined(OS_LINUX) || defined(OS_MAC)
   int32_t result = SyncCall<PpapiPluginMsg_Flash_GetLocalTimeZoneOffsetReply>(
       BROWSER,
       PpapiHostMsg_Flash_GetLocalTimeZoneOffset(PPTimeToTime(t)),

ppapi/proxy/nacl_message_scanner.cc

@@ -353,7 +353,7 @@ bool NaClMessageScanner::ScanMessage(
   DCHECK(!new_msg_ptr->get());
 
   bool rewrite_msg =
-#if defined(OS_WIN) || defined(OS_MACOSX)
+#if defined(OS_WIN) || defined(OS_MAC)
       true;
 #else
       false;

ppapi/shared_impl/ppapi_constants.h

@@ -13,7 +13,7 @@ namespace ppapi {
 #if defined(OS_WIN)
 const char kCorbTestPluginName[] = "corb_test_plugin.dll";
 const char kPowerSaverTestPluginName[] = "power_saver_test_plugin.dll";
-#elif defined(OS_MACOSX)
+#elif defined(OS_MAC)
 const char kCorbTestPluginName[] = "corb_test_plugin.plugin";
 const char kPowerSaverTestPluginName[] = "power_saver_test_plugin.plugin";
 #elif defined(OS_POSIX)