Remove unused private fields.

Change-Id: I4dc2238f7f6d1e8c654701a87372a8e49f8236a3
diff --git a/Makefile b/Makefile
index e419813..c41fa18 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,7 @@
 CC=/usr/bin/clang
 CXX=/usr/bin/clang
 CLANG_TEST_DEFINE=-DKEYMASTER_CLANG_TEST_BUILD
-COMPILER_SPECIFIC_ARGS=-std=c++11 $(CLANG_TEST_DEFINE)
+COMPILER_SPECIFIC_ARGS=-std=c++11 $(CLANG_TEST_DEFINE) -Wunused-private-field
 else
 COMPILER_SPECIFIC_ARGS=-std=c++0x -fprofile-arcs
 endif
diff --git a/ec_keymaster0_key.cpp b/ec_keymaster0_key.cpp
index 25e550a..5c5ea44 100644
--- a/ec_keymaster0_key.cpp
+++ b/ec_keymaster0_key.cpp
@@ -31,7 +31,7 @@
 
 EcdsaKeymaster0KeyFactory::EcdsaKeymaster0KeyFactory(const SoftKeymasterContext* context,
                                                      const Keymaster0Engine* engine)
-    : EcKeyFactory(context), engine_(engine), soft_context_(context) {
+    : EcKeyFactory(context), engine_(engine) {
 }
 
 keymaster_error_t EcdsaKeymaster0KeyFactory::GenerateKey(const AuthorizationSet& key_description,
diff --git a/ec_keymaster0_key.h b/ec_keymaster0_key.h
index 428c2b5..3bfe7c9 100644
--- a/ec_keymaster0_key.h
+++ b/ec_keymaster0_key.h
@@ -55,7 +55,6 @@
 
   private:
     const Keymaster0Engine* engine_;
-    const SoftKeymasterContext* soft_context_;
 };
 
 class EcKeymaster0Key : public EcKey {
diff --git a/rsa_keymaster0_key.cpp b/rsa_keymaster0_key.cpp
index 80ce2a3..a6e2da3 100644
--- a/rsa_keymaster0_key.cpp
+++ b/rsa_keymaster0_key.cpp
@@ -34,7 +34,7 @@
 
 RsaKeymaster0KeyFactory::RsaKeymaster0KeyFactory(const SoftKeymasterContext* context,
                                                  const Keymaster0Engine* engine)
-    : RsaKeyFactory(context), engine_(engine), soft_context_(context) {
+    : RsaKeyFactory(context), engine_(engine) {
 }
 
 keymaster_error_t RsaKeymaster0KeyFactory::GenerateKey(const AuthorizationSet& key_description,
diff --git a/rsa_keymaster0_key.h b/rsa_keymaster0_key.h
index 2090d04..34a4bdc 100644
--- a/rsa_keymaster0_key.h
+++ b/rsa_keymaster0_key.h
@@ -55,7 +55,6 @@
 
   private:
     const Keymaster0Engine* engine_;
-    const SoftKeymasterContext* soft_context_;
 };
 
 class RsaKeymaster0Key : public RsaKey {