Add CdmFileIOProvider interface for use by cdm_adapter

media/cdm/cdm_adapter_unittest.cc

Index: media/cdm/cdm_adapter_unittest.cc
diff --git a/media/cdm/cdm_adapter_unittest.cc b/media/cdm/cdm_adapter_unittest.cc
index ae743852835e4087128a6ead96869435eaf19573..8a135950f2fe3b4e6efb38b3de063dbb4a09dab5 100644
--- a/media/cdm/cdm_adapter_unittest.cc
+++ b/media/cdm/cdm_adapter_unittest.cc
@@ -15,6 +15,7 @@
 #include "media/cdm/cdm_adapter.h"
 #include "media/cdm/external_clear_key_test_helper.h"
 #include "media/cdm/simple_cdm_allocator.h"
+#include "media/cdm/simple_cdm_file_io_provider.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -82,9 +83,10 @@ class CdmAdapterTest : public testing::Test {
                            ExpectedResult expected_result) {
     CdmConfig cdm_config;  // default settings of false are sufficient.
     scoped_ptr<CdmAllocator> allocator(new SimpleCdmAllocator());
-
+    scoped_ptr<CdmFileIOProvider> provider(new SimpleCdmFileIOProvider());
     CdmAdapter::Create(
         helper_.KeySystemName(), library_path, cdm_config, std::move(allocator),
+        std::move(provider),
         base::Bind(&CdmAdapterTest::OnSessionMessage, base::Unretained(this)),
         base::Bind(&CdmAdapterTest::OnSessionClosed, base::Unretained(this)),
         base::Bind(&CdmAdapterTest::OnLegacySessionError,