Revert 171080

ppapi/c/private/ppb_flash_file.h

Index: ppapi/c/private/ppb_flash_file.h
===================================================================
--- ppapi/c/private/ppb_flash_file.h	(revision 171259)
+++ ppapi/c/private/ppb_flash_file.h	(working copy)
@@ -32,9 +32,18 @@
 // Module-local file paths are '/'-separated UTF-8 strings, relative to a
 // module-specific root.
 struct PPB_Flash_File_ModuleLocal_3_0 {
-  // Deprecated. Returns true.
+  // Does initialization necessary for proxying this interface on background
+  // threads. You must always call this function before using any other
+  // function in this interface for a given instance ID.
+  //
+  // Returns true if multithreaded access is supported. In this case you can
+  // use the rest of the functions from background threads. You may not call
+  // GetInterface or do any other PPAPI operations on background threads at
+  // this time.
   bool (*CreateThreadAdapterForInstance)(PP_Instance instance);
-  // Deprecated. Does nothing.
+
+  // Call when an instance is destroyed when you've previously called
+  // CreateThreadAdapterForInstance.
   void (*ClearThreadAdapterForInstance)(PP_Instance instance);
 
   // Opens a file, returning a file descriptor (posix) or a HANDLE (win32) into