Revert "libbrillo: break SecureAllocator dependence on std::vector<uint8_t>"

This reverts commit 10f3dc438da6f8ade5c0eb90f9cf894e449fe997.

Change-Id: I5231fe6bf31640da9b7dce9d5bf76ae2529ebd2f
diff --git a/brillo/secure_blob.cc b/brillo/secure_blob.cc
index 0c7026a..70950f6 100644
--- a/brillo/secure_blob.cc
+++ b/brillo/secure_blob.cc
@@ -54,25 +54,26 @@
     : SecureBlob(data.begin(), data.end()) {}
 
 SecureBlob::~SecureBlob() {
-  SecureVector::clear();
+  clear();
 }
 
 void SecureBlob::resize(size_type count) {
   if (count < size()) {
     SecureMemset(data() + count, 0, capacity() - count);
   }
-  SecureVector::resize(count);
+  Blob::resize(count);
 }
 
 void SecureBlob::resize(size_type count, const value_type& value) {
   if (count < size()) {
     SecureMemset(data() + count, 0, capacity() - count);
   }
-  SecureVector::resize(count, value);
+  Blob::resize(count, value);
 }
 
 void SecureBlob::clear() {
-  SecureVector::clear();
+  SecureMemset(data(), 0, capacity());
+  Blob::clear();
 }
 
 std::string SecureBlob::to_string() const {
diff --git a/brillo/secure_blob.h b/brillo/secure_blob.h
index e06646d..7705c1a 100644
--- a/brillo/secure_blob.h
+++ b/brillo/secure_blob.h
@@ -11,16 +11,13 @@
 
 #include <brillo/asan.h>
 #include <brillo/brillo_export.h>
-#include <brillo/secure_allocator.h>
 
 namespace brillo {
 
+// TODO(sarthakkukreti): remove temp. SecureVector once we break SecureBlob's
+// dependence on std::vector<uint8_t>
 using Blob = std::vector<uint8_t>;
-// Define SecureVector as a vector using a SecureAllocator.
-// Over time, the goal is to remove the differentiating functions
-// from SecureBlob (to_string(), char_data()) till it converges with
-// SecureVector.
-using SecureVector = std::vector<uint8_t, SecureAllocator<uint8_t>>;
+using SecureVector = std::vector<uint8_t>;
 
 // Conversion of Blob to/from std::string, where the string holds raw byte
 // contents.
@@ -32,11 +29,10 @@
 
 // SecureBlob erases the contents on destruction.  It does not guarantee erasure
 // on resize, assign, etc.
-class BRILLO_EXPORT SecureBlob : public SecureVector {
+class BRILLO_EXPORT SecureBlob : public Blob {
  public:
   SecureBlob() = default;
-  // Inherit standard constructors from SecureVector.
-  using SecureVector::vector;
+  using Blob::vector;  // Inherit standard constructors from vector.
   explicit SecureBlob(const Blob& blob);
   explicit SecureBlob(const std::string& data);
   ~SecureBlob();