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

content/browser/renderer_host/pepper/pepper_printing_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 "content/browser/renderer_host/pepper/browser_ppapi_host_test.h"
 #include "content/browser/renderer_host/pepper/pepper_print_settings_manager.h"
 #include "content/browser/renderer_host/pepper/pepper_printing_host.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/host/host_message_context.h"
 #include "ppapi/host/ppapi_host.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/resource_message_params.h"
 #include "ppapi/proxy/resource_message_test_sink.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
 
 namespace {
 
 // Mock implementation of |PepperPrintSettingsManager| for test purposes.
 class MockPepperPrintSettingsManager
     : public PepperPrintSettingsManager {
  public:
-  MockPepperPrintSettingsManager(const PP_PrintSettings_Dev& settings);
+  explicit MockPepperPrintSettingsManager(const PP_PrintSettings_Dev& settings);
   virtual ~MockPepperPrintSettingsManager() {}
 
   // PepperPrintSettingsManager implementation.
   virtual void GetDefaultPrintSettings(
       PepperPrintSettingsManager::Callback callback) OVERRIDE;
  private:
   PP_PrintSettings_Dev settings_;
 
   DISALLOW_COPY_AND_ASSIGN(MockPepperPrintSettingsManager);
 };
@@ skipping 84 matching lines @@
                            actual_settings.paper_size));
   EXPECT_EQ(expected_settings.dpi, actual_settings.dpi);
   EXPECT_EQ(expected_settings.orientation, actual_settings.orientation);
   EXPECT_EQ(expected_settings.print_scaling_option,
             actual_settings.print_scaling_option);
   EXPECT_EQ(expected_settings.grayscale, actual_settings.grayscale);
   EXPECT_EQ(expected_settings.format, actual_settings.format);
 }
 
 }  // namespace content