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/cdm/core/include/policy_engine.h

@@ -6,12 +6,12 @@
 #define WVCDM_CORE_POLICY_ENGINE_H_
 
 #include <map>
+#include <memory>
 #include <string>
 
 #include "disallow_copy_and_assign.h"
 #include "license_key_status.h"
 #include "license_protocol.pb.h"
-#include "scoped_ptr.h"
 #include "wv_cdm_types.h"
 
 namespace wvcdm {
@@ -212,14 +212,14 @@ class PolicyEngine {
 
   // Keys associated with license - holds allowed usage, usage constraints,
   // and current status (CdmKeyStatus)
-  scoped_ptr<LicenseKeys> license_keys_;
+  std::unique_ptr<LicenseKeys> license_keys_;
 
   // Device checks
   int64_t next_device_check_;
   uint32_t current_resolution_;
   CryptoSession* crypto_session_;
 
-  scoped_ptr<Clock> clock_;
+  std::unique_ptr<Clock> clock_;
 
   CORE_DISALLOW_COPY_AND_ASSIGN(PolicyEngine);
 };