Replace scoped_ptr With std::unique_ptr

(This is a merge of http://go/wvgerrit/65782)

We have had our own scoped_ptr implementation that is used throughout
the codebase. Now that we support C++11, we can replace these with
std::unique_ptr.

Doing this replacement exposed a few places where the two were not
interchangeable. OEMCrypto Ref was doing some unsafe things with passing
scoped_ptrs to functions and has been updated to use move semantics. And
a few constructors were explicitly constructing a scoped_ptr with NULL,
which is ambiguous with std::unique_ptr. These have been replaced with
default constructor calls.

Bug: 111851141
Test: CE CDM Unit Tests
Test: Android Unit Tests
Change-Id: I37d6d7aad4906709381c74f0c5439f826d2be768

libwvdrmengine/oemcrypto/ref/src/oemcrypto_ref.cpp

@@ -19,6 +19,7 @@
 #include <time.h>
 #include <iostream>
 #include <string>
+#include <utility>
 #include <vector>
 #include "file_store.h"
 #include "log.h"
@@ -64,8 +65,8 @@ extern "C" OEMCryptoResult OEMCrypto_Initialize(void) {
   }
   // NOTE: This requires a compatible Filesystem implementation.
   // NOTE: Ownership of the FileSystem object is transferred to CryptoEngine
-  scoped_ptr<wvcdm::FileSystem> fs(new wvcdm::FileSystem());
-  crypto_engine = CryptoEngine::MakeCryptoEngine(fs);
+  std::unique_ptr<wvcdm::FileSystem> fs(new wvcdm::FileSystem());
+  crypto_engine = CryptoEngine::MakeCryptoEngine(std::move(fs));
 
   if (!crypto_engine || !crypto_engine->Initialize()) {
     LOGE("[OEMCrypto_Initialize(): failed]");