Rename SignatureUtil to BinaryFeatureExtractor in anticipation of it taking on more work.

BUG=None
TBR=sky@chromium.org

Review URL: https://codereview.chromium.org/209333010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@259117 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 106 insertions, 96 deletions

diff --git a/chrome/browser/safe_browsing/binary_feature_extractor.h b/chrome/browser/safe_browsing/binary_feature_extractor.h
new file mode 100644
index 0000000..bbf9b0d
--- /dev/null
+++ b/chrome/browser/safe_browsing/binary_feature_extractor.h
@@ -0,0 +1,41 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Utility functions to extract file features for malicious binary detection.
+// Each platform has its own implementation of this class.
+
+#ifndef CHROME_BROWSER_SAFE_BROWSING_BINARY_FEATURE_EXTRACTOR_H_
+#define CHROME_BROWSER_SAFE_BROWSING_BINARY_FEATURE_EXTRACTOR_H_
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+
+namespace base {
+class FilePath;
+}
+
+namespace safe_browsing {
+class ClientDownloadRequest_SignatureInfo;
+
+class BinaryFeatureExtractor
+    : public base::RefCountedThreadSafe<BinaryFeatureExtractor> {
+ public:
+  BinaryFeatureExtractor();
+
+  // Fills in the DownloadRequest_SignatureInfo for the given file path.
+  // This method may be called on any thread.
+  virtual void CheckSignature(
+      const base::FilePath& file_path,
+      ClientDownloadRequest_SignatureInfo* signature_info);
+
+ protected:
+  friend class base::RefCountedThreadSafe<BinaryFeatureExtractor>;
+  virtual ~BinaryFeatureExtractor();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(BinaryFeatureExtractor);
+};
+}  // namespace safe_browsing
+
+#endif  // CHROME_BROWSER_SAFE_BROWSING_BINARY_FEATURE_EXTRACTOR_H_
diff --git a/chrome/browser/safe_browsing/signature_util_posix.cc b/chrome/browser/safe_browsing/binary_feature_extractor_posix.cc
index 7a98a54..a1dafc5 100644
--- a/chrome/browser/safe_browsing/signature_util_posix.cc
+++ b/chrome/browser/safe_browsing/binary_feature_extractor_posix.cc
@@ -1,19 +1,19 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This is a stub for the code signing utilities on Mac and Linux.
 // It should eventually be replaced with a real implementation.
 
-#include "chrome/browser/safe_browsing/signature_util.h"
+#include "chrome/browser/safe_browsing/binary_feature_extractor.h"
 
 namespace safe_browsing {
 
-SignatureUtil::SignatureUtil() {}
+BinaryFeatureExtractor::BinaryFeatureExtractor() {}
 
-SignatureUtil::~SignatureUtil() {}
+BinaryFeatureExtractor::~BinaryFeatureExtractor() {}
 
-void SignatureUtil::CheckSignature(
+void BinaryFeatureExtractor::CheckSignature(
     const base::FilePath& file_path,
     ClientDownloadRequest_SignatureInfo* signature_info) {}
 
diff --git a/chrome/browser/safe_browsing/signature_util_win.cc b/chrome/browser/safe_browsing/binary_feature_extractor_win.cc
index b512fca..243b497 100644
--- a/chrome/browser/safe_browsing/signature_util_win.cc
+++ b/chrome/browser/safe_browsing/binary_feature_extractor_win.cc
@@ -1,8 +1,8 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/safe_browsing/signature_util.h"
+#include "chrome/browser/safe_browsing/binary_feature_extractor.h"
 
 #include <windows.h>
 #include <softpub.h>
@@ -16,11 +16,11 @@
 
 namespace safe_browsing {
 
-SignatureUtil::SignatureUtil() {}
+BinaryFeatureExtractor::BinaryFeatureExtractor() {}
 
-SignatureUtil::~SignatureUtil() {}
+BinaryFeatureExtractor::~BinaryFeatureExtractor() {}
 
-void SignatureUtil::CheckSignature(
+void BinaryFeatureExtractor::CheckSignature(
     const base::FilePath& file_path,
     ClientDownloadRequest_SignatureInfo* signature_info) {
   VLOG(2) << "Checking signature for " << file_path.value();
diff --git a/chrome/browser/safe_browsing/signature_util_win_unittest.cc b/chrome/browser/safe_browsing/binary_feature_extractor_win_unittest.cc
index 294a8e9..31a4b41 100644
--- a/chrome/browser/safe_browsing/signature_util_win_unittest.cc
+++ b/chrome/browser/safe_browsing/binary_feature_extractor_win_unittest.cc
@@ -1,8 +1,8 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/safe_browsing/signature_util.h"
+#include "chrome/browser/safe_browsing/binary_feature_extractor.h"
 
 #include <string>
 #include <vector>
@@ -18,7 +18,7 @@
 
 namespace safe_browsing {
 
-class SignatureUtilWinTest : public testing::Test {
+class BinaryFeatureExtractorWinTest : public testing::Test {
  protected:
   virtual void SetUp() {
     base::FilePath source_path;
@@ -46,9 +46,10 @@ class SignatureUtilWinTest : public testing::Test {
   base::FilePath testdata_path_;
 };
 
-TEST_F(SignatureUtilWinTest, UntrustedSignedBinary) {
+TEST_F(BinaryFeatureExtractorWinTest, UntrustedSignedBinary) {
   // signed.exe is signed by an untrusted root CA.
-  scoped_refptr<SignatureUtil> signature_util(new SignatureUtil());
+  scoped_refptr<BinaryFeatureExtractor> signature_util(
+      new BinaryFeatureExtractor());
   ClientDownloadRequest_SignatureInfo signature_info;
   signature_util->CheckSignature(testdata_path_.Append(L"signed.exe"),
                                  &signature_info);
@@ -63,9 +64,10 @@ TEST_F(SignatureUtilWinTest, UntrustedSignedBinary) {
   EXPECT_FALSE(signature_info.trusted());
 }
 
-TEST_F(SignatureUtilWinTest, TrustedBinary) {
+TEST_F(BinaryFeatureExtractorWinTest, TrustedBinary) {
   // wow_helper.exe is signed using Google's signing certifiacte.
-  scoped_refptr<SignatureUtil> signature_util(new SignatureUtil());
+  scoped_refptr<BinaryFeatureExtractor> signature_util(
+      new BinaryFeatureExtractor());
   ClientDownloadRequest_SignatureInfo signature_info;
   signature_util->CheckSignature(testdata_path_.Append(L"wow_helper.exe"),
                                  &signature_info);
@@ -83,9 +85,10 @@ TEST_F(SignatureUtilWinTest, TrustedBinary) {
   EXPECT_TRUE(signature_info.trusted());
 }
 
-TEST_F(SignatureUtilWinTest, UnsignedBinary) {
+TEST_F(BinaryFeatureExtractorWinTest, UnsignedBinary) {
   // unsigned.exe has no signature information.
-  scoped_refptr<SignatureUtil> signature_util(new SignatureUtil());
+  scoped_refptr<BinaryFeatureExtractor> signature_util(
+      new BinaryFeatureExtractor());
   ClientDownloadRequest_SignatureInfo signature_info;
   signature_util->CheckSignature(testdata_path_.Append(L"unsigned.exe"),
                                  &signature_info);
@@ -93,9 +96,10 @@ TEST_F(SignatureUtilWinTest, UnsignedBinary) {
   EXPECT_FALSE(signature_info.has_trusted());
 }
 
-TEST_F(SignatureUtilWinTest, NonExistentBinary) {
+TEST_F(BinaryFeatureExtractorWinTest, NonExistentBinary) {
   // Test a file that doesn't exist.
-  scoped_refptr<SignatureUtil> signature_util(new SignatureUtil());
+  scoped_refptr<BinaryFeatureExtractor> signature_util(
+      new BinaryFeatureExtractor());
   ClientDownloadRequest_SignatureInfo signature_info;
   signature_util->CheckSignature(testdata_path_.Append(L"doesnotexist.exe"),
                                  &signature_info);
diff --git a/chrome/browser/safe_browsing/download_protection_service.cc b/chrome/browser/safe_browsing/download_protection_service.cc
index 8a9f6e1..26d79f5 100644
--- a/chrome/browser/safe_browsing/download_protection_service.cc
+++ b/chrome/browser/safe_browsing/download_protection_service.cc
@@ -18,10 +18,10 @@
 #include "base/strings/stringprintf.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/time/time.h"
+#include "chrome/browser/safe_browsing/binary_feature_extractor.h"
 #include "chrome/browser/safe_browsing/download_feedback_service.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "chrome/browser/safe_browsing/sandboxed_zip_analyzer.h"
-#include "chrome/browser/safe_browsing/signature_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/common/safe_browsing/csd.pb.h"
@@ -280,14 +280,14 @@ class DownloadProtectionService::CheckClientDownloadRequest
       const CheckDownloadCallback& callback,
       DownloadProtectionService* service,
       const scoped_refptr<SafeBrowsingDatabaseManager>& database_manager,
-      SignatureUtil* signature_util)
+      BinaryFeatureExtractor* binary_feature_extractor)
       : item_(item),
         url_chain_(item->GetUrlChain()),
         referrer_url_(item->GetReferrerUrl()),
         zipped_executable_(false),
         callback_(callback),
         service_(service),
-        signature_util_(signature_util),
+        binary_feature_extractor_(binary_feature_extractor),
         database_manager_(database_manager),
         pingback_enabled_(service_->enabled()),
         finished_(false),
@@ -335,7 +335,7 @@ class DownloadProtectionService::CheckClientDownloadRequest
     } else {
       DCHECK(!download_protection_util::IsArchiveFile(
           item_->GetTargetFilePath()));
-      StartExtractSignatureFeatures();
+      StartExtractFileFeatures();
     }
   }
 
@@ -496,21 +496,21 @@ class DownloadProtectionService::CheckClientDownloadRequest
         base::Bind(&CheckClientDownloadRequest::StartTimeout, this));
   }
 
-  void StartExtractSignatureFeatures() {
+  void StartExtractFileFeatures() {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     DCHECK(item_);  // Called directly from Start(), item should still exist.
     // Since we do blocking I/O, offload this to a worker thread.
     // The task does not need to block shutdown.
     BrowserThread::GetBlockingPool()->PostWorkerTaskWithShutdownBehavior(
         FROM_HERE,
-        base::Bind(&CheckClientDownloadRequest::ExtractSignatureFeatures,
+        base::Bind(&CheckClientDownloadRequest::ExtractFileFeatures,
                    this, item_->GetFullPath()),
         base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
   }
 
-  void ExtractSignatureFeatures(const base::FilePath& file_path) {
+  void ExtractFileFeatures(const base::FilePath& file_path) {
     base::TimeTicks start_time = base::TimeTicks::Now();
-    signature_util_->CheckSignature(file_path, &signature_info_);
+    binary_feature_extractor_->CheckSignature(file_path, &signature_info_);
     bool is_signed = (signature_info_.certificate_chain_size() > 0);
     if (is_signed) {
       VLOG(2) << "Downloaded a signed binary: " << file_path.value();
@@ -753,7 +753,7 @@ class DownloadProtectionService::CheckClientDownloadRequest
   CheckDownloadCallback callback_;
   // Will be NULL if the request has been canceled.
   DownloadProtectionService* service_;
-  scoped_refptr<SignatureUtil> signature_util_;
+  scoped_refptr<BinaryFeatureExtractor> binary_feature_extractor_;
   scoped_refptr<SafeBrowsingDatabaseManager> database_manager_;
   const bool pingback_enabled_;
   scoped_ptr<net::URLFetcher> fetcher_;
@@ -773,7 +773,7 @@ DownloadProtectionService::DownloadProtectionService(
     net::URLRequestContextGetter* request_context_getter)
     : request_context_getter_(request_context_getter),
       enabled_(false),
-      signature_util_(new SignatureUtil()),
+      binary_feature_extractor_(new BinaryFeatureExtractor()),
       download_request_timeout_ms_(kDownloadRequestTimeoutMs),
       feedback_service_(new DownloadFeedbackService(
           request_context_getter, BrowserThread::GetBlockingPool())) {
@@ -805,7 +805,8 @@ void DownloadProtectionService::CheckClientDownload(
     const CheckDownloadCallback& callback) {
   scoped_refptr<CheckClientDownloadRequest> request(
       new CheckClientDownloadRequest(item, callback, this,
-                                     database_manager_, signature_util_.get()));
+                                     database_manager_,
+                                     binary_feature_extractor_.get()));
   download_requests_.insert(request);
   request->Start();
 }
diff --git a/chrome/browser/safe_browsing/download_protection_service.h b/chrome/browser/safe_browsing/download_protection_service.h
index 609fdcf..0b5f69f 100644
--- a/chrome/browser/safe_browsing/download_protection_service.h
+++ b/chrome/browser/safe_browsing/download_protection_service.h
@@ -34,7 +34,7 @@ class X509Certificate;
 
 namespace safe_browsing {
 class DownloadFeedbackService;
-class SignatureUtil;
+class BinaryFeatureExtractor;
 
 // This class provides an asynchronous API to check whether a particular
 // client download is malicious or not.
@@ -190,8 +190,8 @@ class DownloadProtectionService {
   // Keeps track of the state of the service.
   bool enabled_;
 
-  // SignatureUtil object, may be overridden for testing.
-  scoped_refptr<SignatureUtil> signature_util_;
+  // BinaryFeatureExtractor object, may be overridden for testing.
+  scoped_refptr<BinaryFeatureExtractor> binary_feature_extractor_;
 
   int64 download_request_timeout_ms_;
 
diff --git a/chrome/browser/safe_browsing/download_protection_service_unittest.cc b/chrome/browser/safe_browsing/download_protection_service_unittest.cc
index ee82e27..bfd903e 100644
--- a/chrome/browser/safe_browsing/download_protection_service_unittest.cc
+++ b/chrome/browser/safe_browsing/download_protection_service_unittest.cc
@@ -20,10 +20,10 @@
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
+#include "chrome/browser/safe_browsing/binary_feature_extractor.h"
 #include "chrome/browser/safe_browsing/database_manager.h"
 #include "chrome/browser/safe_browsing/download_feedback_service.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
-#include "chrome/browser/safe_browsing/signature_util.h"
 #include "chrome/common/safe_browsing/csd.pb.h"
 #include "content/public/test/mock_download_item.h"
 #include "content/public/test/test_browser_thread_bundle.h"
@@ -95,17 +95,17 @@ class FakeSafeBrowsingService : public SafeBrowsingService {
   DISALLOW_COPY_AND_ASSIGN(FakeSafeBrowsingService);
 };
 
-class MockSignatureUtil : public SignatureUtil {
+class MockBinaryFeatureExtractor : public BinaryFeatureExtractor {
  public:
-  MockSignatureUtil() {}
+  MockBinaryFeatureExtractor() {}
   MOCK_METHOD2(CheckSignature, void (const base::FilePath&,
                                      ClientDownloadRequest_SignatureInfo*));
 
  protected:
-  virtual ~MockSignatureUtil() {}
+  virtual ~MockBinaryFeatureExtractor() {}
 
  private:
-  DISALLOW_COPY_AND_ASSIGN(MockSignatureUtil);
+  DISALLOW_COPY_AND_ASSIGN(MockBinaryFeatureExtractor);
 };
 }  // namespace
 
@@ -161,9 +161,9 @@ class DownloadProtectionServiceTest : public testing::Test {
     // to test that we're on the correct thread work.
     sb_service_ = new StrictMock<FakeSafeBrowsingService>();
     sb_service_->Initialize();
-    signature_util_ = new StrictMock<MockSignatureUtil>();
+    binary_feature_extractor_ = new StrictMock<MockBinaryFeatureExtractor>();
     download_service_ = sb_service_->download_protection_service();
-    download_service_->signature_util_ = signature_util_;
+    download_service_->binary_feature_extractor_ = binary_feature_extractor_;
     download_service_->SetEnabled(true);
     base::RunLoop().RunUntilIdle();
     has_result_ = false;
@@ -311,7 +311,7 @@ class DownloadProtectionServiceTest : public testing::Test {
 
  protected:
   scoped_refptr<FakeSafeBrowsingService> sb_service_;
-  scoped_refptr<MockSignatureUtil> signature_util_;
+  scoped_refptr<MockBinaryFeatureExtractor> binary_feature_extractor_;
   DownloadProtectionService* download_service_;
   DownloadProtectionService::DownloadCheckResult result_;
   bool has_result_;
@@ -383,7 +383,8 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadWhitelistedUrl) {
   EXPECT_CALL(item, GetReceivedBytes()).WillRepeatedly(Return(100));
   EXPECT_CALL(item, HasUserGesture()).WillRepeatedly(Return(true));
   EXPECT_CALL(item, GetRemoteAddress()).WillRepeatedly(Return(""));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(a_tmp, _)).Times(4);
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(a_tmp, _))
+      .Times(4);
 
   // We should not get whilelist checks for other URLs than specified below.
   EXPECT_CALL(*sb_service_->mock_database_manager(),
@@ -473,7 +474,7 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadFetchFailed) {
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(a_tmp, _));
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(a_tmp, _));
 
   download_service_->CheckClientDownload(
       &item,
@@ -515,7 +516,8 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadSuccess) {
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(a_tmp, _)).Times(6);
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(a_tmp, _))
+      .Times(6);
 
   download_service_->CheckClientDownload(
       &item,
@@ -659,7 +661,8 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadHTTPS) {
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(a_tmp, _)).Times(1);
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(a_tmp, _))
+      .Times(1);
 
   download_service_->CheckClientDownload(
       &item,
@@ -722,7 +725,7 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadZip) {
   MessageLoop::current()->Run();
   EXPECT_TRUE(IsResult(DownloadProtectionService::SAFE));
   Mock::VerifyAndClearExpectations(sb_service_.get());
-  Mock::VerifyAndClearExpectations(signature_util_.get());
+  Mock::VerifyAndClearExpectations(binary_feature_extractor_.get());
 
   // Now check with an executable in the zip file as well.
   ASSERT_EQ(static_cast<int>(file_contents.size()), base::WriteFile(
@@ -740,7 +743,7 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadZip) {
                  base::Unretained(this)));
   MessageLoop::current()->Run();
   EXPECT_TRUE(IsResult(DownloadProtectionService::SAFE));
-  Mock::VerifyAndClearExpectations(signature_util_.get());
+  Mock::VerifyAndClearExpectations(binary_feature_extractor_.get());
 
   // If the response is dangerous the result should also be marked as
   // dangerous.
@@ -760,7 +763,7 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadZip) {
 #else
   EXPECT_TRUE(IsResult(DownloadProtectionService::SAFE));
 #endif
-  Mock::VerifyAndClearExpectations(signature_util_.get());
+  Mock::VerifyAndClearExpectations(binary_feature_extractor_.get());
 }
 
 TEST_F(DownloadProtectionServiceTest, CheckClientDownloadCorruptZip) {
@@ -797,7 +800,7 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadCorruptZip) {
   MessageLoop::current()->Run();
   EXPECT_TRUE(IsResult(DownloadProtectionService::SAFE));
   Mock::VerifyAndClearExpectations(sb_service_.get());
-  Mock::VerifyAndClearExpectations(signature_util_.get());
+  Mock::VerifyAndClearExpectations(binary_feature_extractor_.get());
 }
 
 TEST_F(DownloadProtectionServiceTest, CheckClientCrxDownloadSuccess) {
@@ -835,7 +838,8 @@ TEST_F(DownloadProtectionServiceTest, CheckClientCrxDownloadSuccess) {
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(a_tmp, _)).Times(1);
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(a_tmp, _))
+      .Times(1);
 
   EXPECT_FALSE(download_service_->IsSupportedDownload(item, a_crx));
   download_service_->CheckClientDownload(
@@ -873,7 +877,7 @@ TEST_F(DownloadProtectionServiceTest, CheckClientDownloadValidateRequest) {
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(tmp_path, _))
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(tmp_path, _))
       .WillOnce(SetCertificateContents("dummy cert data"));
   download_service_->CheckClientDownload(
       &item,
@@ -950,7 +954,7 @@ TEST_F(DownloadProtectionServiceTest,
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(tmp_path, _));
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(tmp_path, _));
   download_service_->CheckClientDownload(
       &item,
       base::Bind(&DownloadProtectionServiceTest::CheckDoneCallback,
@@ -1082,7 +1086,7 @@ TEST_F(DownloadProtectionServiceTest, TestDownloadRequestTimeout) {
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(tmp_path, _));
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(tmp_path, _));
 
   download_service_->download_request_timeout_ms_ = 10;
   download_service_->CheckClientDownload(
@@ -1123,7 +1127,7 @@ TEST_F(DownloadProtectionServiceTest, TestDownloadItemDestroyed) {
   EXPECT_CALL(*sb_service_->mock_database_manager(),
               MatchDownloadWhitelistUrl(_))
       .WillRepeatedly(Return(false));
-  EXPECT_CALL(*signature_util_.get(), CheckSignature(tmp_path, _));
+  EXPECT_CALL(*binary_feature_extractor_.get(), CheckSignature(tmp_path, _));
 
   download_service_->CheckClientDownload(
       &item,
diff --git a/chrome/browser/safe_browsing/signature_util.h b/chrome/browser/safe_browsing/signature_util.h
deleted file mode 100644
index 00aef61..0000000
--- a/chrome/browser/safe_browsing/signature_util.h
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-//
-// Utility functions to check executable signatures for malicious binary
-// detection.  Each platform has its own implementation of this class.
-
-#ifndef CHROME_BROWSER_SAFE_BROWSING_SIGNATURE_UTIL_H_
-#define CHROME_BROWSER_SAFE_BROWSING_SIGNATURE_UTIL_H_
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-
-namespace base {
-class FilePath;
-}
-
-namespace safe_browsing {
-class ClientDownloadRequest_SignatureInfo;
-
-class SignatureUtil : public base::RefCountedThreadSafe<SignatureUtil> {
- public:
-  SignatureUtil();
-
-  // Fills in the DownloadRequest_SignatureInfo for the given file path.
-  // This method may be called on any thread.
-  virtual void CheckSignature(
-      const base::FilePath& file_path,
-      ClientDownloadRequest_SignatureInfo* signature_info);
-
- protected:
-  friend class base::RefCountedThreadSafe<SignatureUtil>;
-  virtual ~SignatureUtil();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(SignatureUtil);
-};
-}  // namespace safe_browsing
-
-#endif  // CHROME_BROWSER_SAFE_BROWSING_SIGNATURE_UTIL_H_