Add a size parameter to SharedMemoryHandle.

base/memory/shared_memory_android.cc

Index: base/memory/shared_memory_android.cc
diff --git a/base/memory/shared_memory_android.cc b/base/memory/shared_memory_android.cc
index da3c5953f044c8ca861427f7cecfd3661b60f930..5765403b26e7d63f6dc90c6a1d288ca6521fdd05 100644
--- a/base/memory/shared_memory_android.cc
+++ b/base/memory/shared_memory_android.cc
@@ -27,7 +27,7 @@ bool SharedMemory::Create(const SharedMemoryCreateOptions& options) {
   int fd = ashmem_create_region(
       options.name_deprecated == NULL ? "" : options.name_deprecated->c_str(),
       options.size);
-  shm_ = SharedMemoryHandle::ImportHandle(fd);
+  shm_ = SharedMemoryHandle::ImportHandle(fd, options.size);
   if (!shm_.IsValid()) {
     DLOG(ERROR) << "Shared memory creation failed";
     return false;
@@ -42,8 +42,9 @@ bool SharedMemory::Create(const SharedMemoryCreateOptions& options) {
 
   // Android doesn't appear to have a way to drop write access on an ashmem
   // segment for a single descriptor.  http://crbug.com/320865
-  readonly_shm_ = SharedMemoryHandle(
-      base::FileDescriptor(dup(shm_.GetHandle()), false), shm_.GetGUID());
+  readonly_shm_ =
+      SharedMemoryHandle(base::FileDescriptor(dup(shm_.GetHandle()), false),

[Nico, 2017/05/15 22:13:36]

Maybe SharedMemoryHandle should have a ReadonlyDup() method by now?

[erikchen, 2017/05/15 22:57:18]

Actually, the GetReadOnlyHandle method is on SharedMemory, and that's because
the implementation on POSIX requires us to reopen the file, which we no longer
keep around, and thus is done during creation of a shared memory segment.

All of this being said, this code doesn't even drop the protection status, so
Duplicate() is sufficient.

[Nico, 2017/05/15 23:11:55]

I mean, this here and a few other places in this CL iirc call the SMH ctor with
a bunch of arguments that are all accessors on smh. The law of demeter suggests
that this should instead be some well-named method on SMH.

+                         shm_.GetSize(), shm_.GetGUID());
   if (!readonly_shm_.IsValid()) {
     DPLOG(ERROR) << "dup() failed";
     return false;