Code Drop Three (Update Two)

In this update we have:

  - Added the verified platform tests. These tests show how some
    platforms, when verified are allowed to by pass the normal policy
    restrictions. This is done with ChromeOS, thus the name of the
    tests use "chrome_os".

  - Removed WB_RESULT_INVALID_PADDING. This error was when we the
    non-license APIs exposed a AES function with padding. However,
    those functions have been removed from the API and this error is
    no longer used by the API.

  - Tests have been updated to avoid signed-vs-unsigned comparison
    and to use the Chromium path to gTest (which is mocked in this
    library).

  - Tests have been updated to use a new test base and golden data
    system to make them easier to read.

impl/reference/aead_whitebox_impl.cc

@@ -6,10 +6,8 @@
 #include <vector>
 
 #include "base/logging.h"
-#include "base/strings/string_number_conversions.h"
 #include "crypto_utils/crypto_util.h"
 #include "impl/reference/memory_util.h"
-#include "impl/reference/string_view_util.h"
 #include "third_party/boringssl/src/include/openssl/aead.h"
 #include "third_party/boringssl/src/include/openssl/rand.h"
 
@@ -41,8 +39,8 @@ std::vector<uint8_t> DeriveKey(const WB_Aead_Whitebox* whitebox,
   // needs to be some fixed, arbitrary non-trivial string.
   constexpr char kLabel[] = "Covfefe";
 
-  const auto init_data_view = widevine::AsStringView(init_data, init_data_size);
-  const auto context_view = widevine::AsStringView(context, context_size);
+  const std::string init_data_view(init_data, init_data + init_data_size);
+  const std::string context_view(context, context + context_size);
 
   // While we get the key size in bytes, DeriveKey() needs the key size in bits.
   const auto derived_key = widevine::crypto_util::DeriveKey(