Bug 1440199 - Part 3: Remove IPC shared memory IDs. r=froydnj

This code isn't blocking anything, but it's dead and I don't think we
have any plans to use it.

MozReview-Commit-ID: KBoEfLceDns

--HG--
extra : rebase_source : 1eee3d961e249939f02d4cc40a707739eb2a596a

ipc/chromium/src/base/shared_memory.h

@@ -26,10 +26,7 @@ namespace base {
 #if defined(OS_WIN)
 typedef HANDLE SharedMemoryHandle;
 #elif defined(OS_POSIX)
-// A SharedMemoryId is sufficient to identify a given shared memory segment on a
-// system, but insufficient to map it.
 typedef FileDescriptor SharedMemoryHandle;
-typedef ino_t SharedMemoryId;
 #endif
 
 // Platform abstraction for shared memory.  Provides a C++ wrapper
@@ -90,14 +87,6 @@ class SharedMemory {
   // identifier is not portable.
   SharedMemoryHandle handle() const;
 
-#if defined(OS_POSIX)
-  // Return a unique identifier for this shared memory segment. Inode numbers
-  // are technically only unique to a single filesystem. However, we always
-  // allocate shared memory backing files from the same directory, so will end
-  // up on the same filesystem.
-  SharedMemoryId id() const { return inode_; }
-#endif
-
   // Closes the open shared memory segment.
   // It is safe to call Close repeatedly.
   void Close(bool unmap_view = true);
@@ -133,7 +122,6 @@ class SharedMemory {
   HANDLE             mapped_file_;
 #elif defined(OS_POSIX)
   int                mapped_file_;
-  ino_t              inode_;
 #endif
   void*              memory_;
   bool               read_only_;

ipc/chromium/src/base/shared_memory_posix.cc

@@ -22,7 +22,6 @@ namespace base {
 
 SharedMemory::SharedMemory()
     : mapped_file_(-1),
-      inode_(0),
       memory_(NULL),
       read_only_(false),
       max_size_(0) {
@@ -35,13 +34,7 @@ SharedMemory::~SharedMemory() {
 bool SharedMemory::SetHandle(SharedMemoryHandle handle, bool read_only) {
   DCHECK(mapped_file_ == -1);
 
-  struct stat st;
-  if (fstat(handle.fd, &st) < 0) {
-    return false;
-  }
-
   mapped_file_ = handle.fd;
-  inode_ = st.st_ino;
   read_only_ = read_only;
   return true;
 }
@@ -109,11 +102,6 @@ bool SharedMemory::Create(size_t size) {
   mapped_file_ = dup(fileno(fp));
   DCHECK(mapped_file_ >= 0);
 
-  struct stat st;
-  if (fstat(mapped_file_, &st))
-    NOTREACHED();
-  inode_ = st.st_ino;
-
   max_size_ = size;
   return true;
 }