Make SharedMemory track the size that was actually mapped

base/shared_memory_posix.cc

Index: base/shared_memory_posix.cc
===================================================================
--- base/shared_memory_posix.cc	(revision 188553)
+++ base/shared_memory_posix.cc	(working copy)
@@ -42,20 +42,20 @@
 
 SharedMemory::SharedMemory()
     : mapped_file_(-1),
+      inode_(0),
       mapped_size_(0),
-      inode_(0),
       memory_(NULL),
       read_only_(false),
-      created_size_(0) {
+      requested_size_(0) {
 }
 
 SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only)
     : mapped_file_(handle.fd),
+      inode_(0),
       mapped_size_(0),
-      inode_(0),
       memory_(NULL),
       read_only_(read_only),
-      created_size_(0) {
+      requested_size_(0) {
   struct stat st;
   if (fstat(handle.fd, &st) == 0) {
     // If fstat fails, then the file descriptor is invalid and we'll learn this
@@ -67,11 +67,11 @@
 SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only,
                            ProcessHandle process)
     : mapped_file_(handle.fd),
+      inode_(0),
       mapped_size_(0),
-      inode_(0),
       memory_(NULL),
       read_only_(read_only),
-      created_size_(0) {
+      requested_size_(0) {
   // We don't handle this case yet (note the ignored parameter); let's die if
   // someone comes calling.
   NOTREACHED();
@@ -164,7 +164,7 @@
         return false;
       }
     }
-    created_size_ = options.size;
+    requested_size_ = options.size;
   }
   if (fp == NULL) {
 #if !defined(OS_MACOSX)
@@ -223,28 +223,28 @@
   if (bytes > static_cast<size_t>(std::numeric_limits<int>::max()))
     return false;
 
-#if defined(OS_ANDROID)
-  if (bytes == 0) {
-    int ashmem_bytes = ashmem_get_size_region(mapped_file_);
-    if (ashmem_bytes < 0)
-      return false;
-
-    DCHECK_GE(static_cast<uint32>(ashmem_bytes), bytes);
-    // The caller wants to determine the map region size from ashmem.
-    bytes = ashmem_bytes - offset;
-    // TODO(port): we set the created size here so that it is available in
-    // transport_dib_android.cc. We should use ashmem_get_size_region()
-    // in transport_dib_android.cc.
-    created_size_ = ashmem_bytes;
-  }
-#endif
-
   memory_ = mmap(NULL, bytes, PROT_READ | (read_only_ ? 0 : PROT_WRITE),
                  MAP_SHARED, mapped_file_, offset);
 
   bool mmap_succeeded = memory_ != (void*)-1 && memory_ != NULL;
   if (mmap_succeeded) {
     mapped_size_ = bytes;
+#if defined(OS_ANDROID)
+    if (bytes == 0) {
+      int ashmem_bytes = ashmem_get_size_region(mapped_file_);
+      if (ashmem_bytes < 0)
+        return false;
+
+      DCHECK_GE(static_cast<uint32>(ashmem_bytes), bytes);
+      // The caller wants to determine the map region size from ashmem.
+      bytes = ashmem_bytes - offset;
+      // TODO(port): we set the created size here so that it is available in
+      // transport_dib_android.cc. We should use ashmem_get_size_region()
+      // in transport_dib_android.cc.
+      mapped_size_ = ashmem_bytes;
+    }
+#endif
+
     DCHECK_EQ(0U, reinterpret_cast<uintptr_t>(memory_) &
         (SharedMemory::MAP_MINIMUM_ALIGNMENT - 1));
   } else {