Add missing (and remove superfluous) 'explicit' from constructors.

chrome/browser/safe_browsing/client_side_detection_host_unittest.cc

 // Copyright (c) 2012 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 "base/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/waitable_event.h"
 #include "chrome/browser/safe_browsing/browser_feature_extractor.h"
 #include "chrome/browser/safe_browsing/client_side_detection_host.h"
@@ skipping 129 matching lines @@
 class MockTestingProfile : public TestingProfile {
  public:
   MockTestingProfile() {}
   virtual ~MockTestingProfile() {}
 
   MOCK_CONST_METHOD0(IsOffTheRecord, bool());
 };
 
 class MockBrowserFeatureExtractor : public BrowserFeatureExtractor {
  public:
-  explicit MockBrowserFeatureExtractor(
+  MockBrowserFeatureExtractor(
       WebContents* tab,
       ClientSideDetectionService* service)
       : BrowserFeatureExtractor(tab, service) {}
   virtual ~MockBrowserFeatureExtractor() {}
 
   MOCK_METHOD3(ExtractFeatures,
                void(const BrowseInfo* info,
                     ClientPhishingRequest*,
                     const BrowserFeatureExtractor::DoneCallback&));
 };
@@ skipping 623 matching lines @@
   EXPECT_TRUE(Mock::VerifyAndClear(ui_manager_.get()));
   EXPECT_EQ(url, resource.url);
   EXPECT_EQ(url, resource.original_url);
   resource.callback.Reset();
   msg = process()->sink().GetFirstMessageMatching(
       SafeBrowsingMsg_StartPhishingDetection::ID);
   ASSERT_FALSE(msg);
 }
 
 }  // namespace safe_browsing