Add a new GetInstance() method for singleton classes, take 2.

This is a small step towards making all singleton classes use the Singleton<T> pattern within their code and not expect the callers to know about it.

This CL includes all files except those under chrome/browser, chrome/net, chrome/service and third_party/WebKit (these will be done in future CLs).

Suggested files to focus for reviewers:
- joi@ for files under src/ceee
- tommi@ for files under src/chrome_frame
- maruel@ for the rest of the files.

BUG=65298
TEST=all existing tests should continue to pass.

Review URL: http://codereview.chromium.org/5581008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68577 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 86 insertions, 66 deletions

diff --git a/chrome_frame/chrome_tab.cc b/chrome_frame/chrome_tab.cc
index a08f2b3..f3f4bd1 100644
--- a/chrome_frame/chrome_tab.cc
+++ b/chrome_frame/chrome_tab.cc
@@ -212,7 +212,7 @@ extern "C" BOOL WINAPI DllMain(HINSTANCE instance,
     logging::InitLogging(NULL, logging::LOG_ONLY_TO_SYSTEM_DEBUG_LOG,
                         logging::LOCK_LOG_FILE, logging::DELETE_OLD_LOG_FILE);
 
-    DllRedirector* dll_redirector = Singleton<DllRedirector>::get();
+    DllRedirector* dll_redirector = DllRedirector::GetInstance();
     DCHECK(dll_redirector);
 
     if (!dll_redirector->RegisterAsFirstCFModule()) {
@@ -227,7 +227,7 @@ extern "C" BOOL WINAPI DllMain(HINSTANCE instance,
     // Enable ETW logging.
     logging::LogEventProvider::Initialize(kChromeFrameProvider);
   } else if (reason == DLL_PROCESS_DETACH) {
-    DllRedirector* dll_redirector = Singleton<DllRedirector>::get();
+    DllRedirector* dll_redirector = DllRedirector::GetInstance();
     DCHECK(dll_redirector);
 
     dll_redirector->UnregisterAsFirstCFModule();
diff --git a/chrome_frame/dll_redirector.cc b/chrome_frame/dll_redirector.cc
index c6fe8cb..97143a7 100644
--- a/chrome_frame/dll_redirector.cc
+++ b/chrome_frame/dll_redirector.cc
@@ -46,6 +46,11 @@ DllRedirector::~DllRedirector() {
   UnregisterAsFirstCFModule();
 }
 
+// static
+DllRedirector* DllRedirector::GetInstance() {
+  return Singleton<DllRedirector>::get();
+}
+
 bool DllRedirector::BuildSecurityAttributesForLock(
     CSecurityAttributes* sec_attr) {
   DCHECK(sec_attr);
diff --git a/chrome_frame/dll_redirector.h b/chrome_frame/dll_redirector.h
index be8a89b..1e12629 100644
--- a/chrome_frame/dll_redirector.h
+++ b/chrome_frame/dll_redirector.h
@@ -33,6 +33,9 @@ class Version;
 //  3) The module this is compiled into is built with version info.
 class DllRedirector {
  public:
+  // Returns the singleton instance.
+  static DllRedirector* GetInstance();
+
   virtual ~DllRedirector();
 
   // Attempts to register this Chrome Frame version as the first loaded version
diff --git a/chrome_frame/policy_settings.cc b/chrome_frame/policy_settings.cc
index 1a35d67..50e465f 100644
--- a/chrome_frame/policy_settings.cc
+++ b/chrome_frame/policy_settings.cc
@@ -153,3 +153,7 @@ void PolicySettings::RefreshFromRegistry() {
   swap(application_locale_, application_locale);
 }
 
+// static
+PolicySettings* PolicySettings::GetInstance() {
+  return Singleton<PolicySettings>::get();
+}
diff --git a/chrome_frame/policy_settings.h b/chrome_frame/policy_settings.h
index 28182bd..72e32d2 100644
--- a/chrome_frame/policy_settings.h
+++ b/chrome_frame/policy_settings.h
@@ -7,6 +7,7 @@
 
 #include <string>
 #include <vector>
+#include "base/singleton.h"
 
 #include "base/basictypes.h"
 
@@ -21,12 +22,7 @@ class PolicySettings {
     RENDER_IN_CHROME_FRAME,
   };
 
-  PolicySettings() : default_renderer_(RENDERER_NOT_SPECIFIED) {
-    RefreshFromRegistry();
-  }
-
-  ~PolicySettings() {
-  }
+  static PolicySettings* GetInstance();
 
   RendererForUrl default_renderer() const {
     return default_renderer_;
@@ -50,6 +46,13 @@ class PolicySettings {
   static void ReadApplicationLocaleSetting(std::wstring* application_locale);
 
  protected:
+  PolicySettings() : default_renderer_(RENDERER_NOT_SPECIFIED) {
+    RefreshFromRegistry();
+  }
+
+  ~PolicySettings() {
+  }
+
   // Protected for now since the class is not thread safe.
   void RefreshFromRegistry();
 
@@ -60,8 +63,9 @@ class PolicySettings {
   std::wstring application_locale_;
 
  private:
+  // This ensures no construction is possible outside of the class itself.
+  friend struct DefaultSingletonTraits<PolicySettings>;
   DISALLOW_COPY_AND_ASSIGN(PolicySettings);
 };
 
-
 #endif  // CHROME_FRAME_POLICY_SETTINGS_H_
diff --git a/chrome_frame/protocol_sink_wrap.cc b/chrome_frame/protocol_sink_wrap.cc
index 0ea330f..64d9048 100644
--- a/chrome_frame/protocol_sink_wrap.cc
+++ b/chrome_frame/protocol_sink_wrap.cc
@@ -232,9 +232,8 @@ bool IsAdditionallySupportedContentType(const wchar_t* status_text) {
       return true;
   }
 
-  Singleton<PolicySettings> policy;
-  if (policy->GetRendererForContentType(status_text) ==
-      PolicySettings::RENDER_IN_CHROME_FRAME) {
+  if (PolicySettings::GetInstance()->GetRendererForContentType(
+      status_text) == PolicySettings::RENDER_IN_CHROME_FRAME) {
     return true;
   }
 
diff --git a/chrome_frame/simple_resource_loader.cc b/chrome_frame/simple_resource_loader.cc
index 89a51d7..324c5ca 100644
--- a/chrome_frame/simple_resource_loader.cc
+++ b/chrome_frame/simple_resource_loader.cc
@@ -88,8 +88,9 @@ SimpleResourceLoader::SimpleResourceLoader()
   std::vector<std::wstring> language_tags;
 
   // First, try the locale dictated by policy and its fallback.
-  PushBackWithFallbackIfAbsent(Singleton<PolicySettings>()->ApplicationLocale(),
-                               &language_tags);
+  PushBackWithFallbackIfAbsent(
+      PolicySettings::GetInstance()->ApplicationLocale(),
+      &language_tags);
 
   // Next, try the thread, process, user, system languages.
   GetPreferredLanguages(&language_tags);
@@ -115,6 +116,11 @@ SimpleResourceLoader::~SimpleResourceLoader() {
 }
 
 // static
+SimpleResourceLoader* SimpleResourceLoader::instance() {
+  return Singleton<SimpleResourceLoader>::get();
+}
+
+// static
 void SimpleResourceLoader::GetPreferredLanguages(
     std::vector<std::wstring>* language_tags) {
   DCHECK(language_tags);
diff --git a/chrome_frame/simple_resource_loader.h b/chrome_frame/simple_resource_loader.h
index c749052..45d03ed 100644
--- a/chrome_frame/simple_resource_loader.h
+++ b/chrome_frame/simple_resource_loader.h
@@ -21,9 +21,7 @@
 class SimpleResourceLoader {
  public:
 
-  static SimpleResourceLoader* instance() {
-    return Singleton<SimpleResourceLoader>::get();
-  }
+  static SimpleResourceLoader* instance();
 
   // Returns the language tag for the active language.
   static std::wstring GetLanguage();
diff --git a/chrome_frame/test/policy_settings_unittest.cc b/chrome_frame/test/policy_settings_unittest.cc
index 55a0b32..53c4df0 100644
--- a/chrome_frame/test/policy_settings_unittest.cc
+++ b/chrome_frame/test/policy_settings_unittest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/basictypes.h"
+#include "base/at_exit.h"
 #include "base/logging.h"
 #include "base/scoped_ptr.h"
 #include "base/stringprintf.h"
@@ -132,14 +133,34 @@ bool SetChromeApplicationLocale(HKEY policy_root, const wchar_t* locale) {
 
 }  // end namespace
 
-TEST(PolicySettings, RendererForUrl) {
-  TempRegKeyOverride::DeleteAllTempKeys();
+class PolicySettingsTest : public testing::Test {
+ protected:
+  void SetUp() {
+    TempRegKeyOverride::DeleteAllTempKeys();
+
+    hklm_pol_.reset(new TempRegKeyOverride(HKEY_LOCAL_MACHINE, L"hklm_pol"));
+    hkcu_pol_.reset(new TempRegKeyOverride(HKEY_CURRENT_USER, L"hkcu_pol"));
+
+    ResetPolicySettings();
+  }
+
+  void TearDown() {
+    hkcu_pol_.reset(NULL);
+    hklm_pol_.reset(NULL);
+    TempRegKeyOverride::DeleteAllTempKeys();
+  }
+
+  void ResetPolicySettings() {
+    at_exit_manager_.ProcessCallbacksNow();
+  }
 
-  scoped_ptr<TempRegKeyOverride> hklm_pol(
-      new TempRegKeyOverride(HKEY_LOCAL_MACHINE, L"hklm_pol"));
-  scoped_ptr<TempRegKeyOverride> hkcu_pol(
-      new TempRegKeyOverride(HKEY_CURRENT_USER, L"hkcu_pol"));
+  // This is used to manage life cycle of PolicySettings singleton.
+  base::ShadowingAtExitManager at_exit_manager_;
+  scoped_ptr<TempRegKeyOverride> hklm_pol_;
+  scoped_ptr<TempRegKeyOverride> hkcu_pol_;
+};
 
+TEST_F(PolicySettingsTest, RendererForUrl) {
   const wchar_t* kTestUrls[] = {
     L"http://www.example.com",
     L"http://www.pattern.com",
@@ -152,11 +173,10 @@ TEST(PolicySettings, RendererForUrl) {
   };
   const wchar_t kNoMatchUrl[] = L"http://www.chromium.org";
 
-  scoped_ptr<PolicySettings> settings(new PolicySettings());
   EXPECT_EQ(PolicySettings::RENDERER_NOT_SPECIFIED,
-            settings->default_renderer());
+            PolicySettings::GetInstance()->default_renderer());
   EXPECT_EQ(PolicySettings::RENDERER_NOT_SPECIFIED,
-            settings->GetRendererForUrl(kNoMatchUrl));
+            PolicySettings::GetInstance()->GetRendererForUrl(kNoMatchUrl));
 
   HKEY root[] = { HKEY_LOCAL_MACHINE, HKEY_CURRENT_USER };
   for (int i = 0; i < arraysize(root); ++i) {
@@ -164,44 +184,33 @@ TEST(PolicySettings, RendererForUrl) {
         PolicySettings::RENDER_IN_CHROME_FRAME, kTestFilters,
         arraysize(kTestFilters)));
 
-    settings.reset(new PolicySettings());
+    ResetPolicySettings();
     EXPECT_EQ(PolicySettings::RENDER_IN_CHROME_FRAME,
-              settings->GetRendererForUrl(kNoMatchUrl));
+              PolicySettings::GetInstance()->GetRendererForUrl(kNoMatchUrl));
     for (int j = 0; j < arraysize(kTestUrls); ++j) {
       EXPECT_EQ(PolicySettings::RENDER_IN_HOST,
-                settings->GetRendererForUrl(kTestUrls[j]));
+                PolicySettings::GetInstance()->GetRendererForUrl(kTestUrls[j]));
     }
 
     EXPECT_TRUE(SetRendererSettings(root[i],
         PolicySettings::RENDER_IN_HOST, NULL, 0));
 
-    settings.reset(new PolicySettings());
+    ResetPolicySettings();
     EXPECT_EQ(PolicySettings::RENDER_IN_HOST,
-              settings->GetRendererForUrl(kNoMatchUrl));
+              PolicySettings::GetInstance()->GetRendererForUrl(kNoMatchUrl));
     for (int j = 0; j < arraysize(kTestUrls); ++j) {
       EXPECT_EQ(PolicySettings::RENDER_IN_HOST,
-                settings->GetRendererForUrl(kTestUrls[j]));
+                PolicySettings::GetInstance()->GetRendererForUrl(kTestUrls[j]));
     }
 
     DeleteChromeFramePolicyEntries(root[i]);
   }
-
-  hkcu_pol.reset(NULL);
-  hklm_pol.reset(NULL);
-  TempRegKeyOverride::DeleteAllTempKeys();
 }
 
-TEST(PolicySettings, RendererForContentType) {
-  TempRegKeyOverride::DeleteAllTempKeys();
-
-  scoped_ptr<TempRegKeyOverride> hklm_pol(
-      new TempRegKeyOverride(HKEY_LOCAL_MACHINE, L"hklm_pol"));
-  scoped_ptr<TempRegKeyOverride> hkcu_pol(
-      new TempRegKeyOverride(HKEY_CURRENT_USER, L"hkcu_pol"));
-
-  scoped_ptr<PolicySettings> settings(new PolicySettings());
+TEST_F(PolicySettingsTest, RendererForContentType) {
   EXPECT_EQ(PolicySettings::RENDERER_NOT_SPECIFIED,
-            settings->GetRendererForContentType(L"text/xml"));
+            PolicySettings::GetInstance()->GetRendererForContentType(
+                L"text/xml"));
 
   const wchar_t* kTestPolicyContentTypes[] = {
     L"application/xml",
@@ -213,39 +222,32 @@ TEST(PolicySettings, RendererForContentType) {
   for (int i = 0; i < arraysize(root); ++i) {
     SetCFContentTypes(root[i], kTestPolicyContentTypes,
                       arraysize(kTestPolicyContentTypes));
-    settings.reset(new PolicySettings());
+    ResetPolicySettings();
     for (int type = 0; type < arraysize(kTestPolicyContentTypes); ++type) {
       EXPECT_EQ(PolicySettings::RENDER_IN_CHROME_FRAME,
-                settings->GetRendererForContentType(
+                PolicySettings::GetInstance()->GetRendererForContentType(
                     kTestPolicyContentTypes[type]));
     }
 
     EXPECT_EQ(PolicySettings::RENDERER_NOT_SPECIFIED,
-              settings->GetRendererForContentType(L"text/html"));
+              PolicySettings::GetInstance()->GetRendererForContentType(
+                  L"text/html"));
 
     DeleteChromeFramePolicyEntries(root[i]);
   }
 }
 
-TEST(PolicySettings, ApplicationLocale) {
-  TempRegKeyOverride::DeleteAllTempKeys();
-
-  scoped_ptr<TempRegKeyOverride> hklm_pol(
-      new TempRegKeyOverride(HKEY_LOCAL_MACHINE, L"hklm_pol"));
-  scoped_ptr<TempRegKeyOverride> hkcu_pol(
-      new TempRegKeyOverride(HKEY_CURRENT_USER, L"hkcu_pol"));
-
-  scoped_ptr<PolicySettings> settings(new PolicySettings());
-  EXPECT_TRUE(settings->ApplicationLocale().empty());
+TEST_F(PolicySettingsTest, ApplicationLocale) {
+  EXPECT_TRUE(PolicySettings::GetInstance()->ApplicationLocale().empty());
 
   static const wchar_t kTestApplicationLocale[] = L"fr-CA";
 
   HKEY root[] = { HKEY_LOCAL_MACHINE, HKEY_CURRENT_USER };
   for (int i = 0; i < arraysize(root); ++i) {
     SetChromeApplicationLocale(root[i], kTestApplicationLocale);
-    settings.reset(new PolicySettings());
+    ResetPolicySettings();
     EXPECT_EQ(std::wstring(kTestApplicationLocale),
-              settings->ApplicationLocale());
+              PolicySettings::GetInstance()->ApplicationLocale());
 
     DeleteChromeFramePolicyEntries(root[i]);
   }
diff --git a/chrome_frame/utils.cc b/chrome_frame/utils.cc
index e4279a7..781d6d4 100644
--- a/chrome_frame/utils.cc
+++ b/chrome_frame/utils.cc
@@ -723,8 +723,8 @@ bool IsGcfDefaultRenderer() {
   DWORD is_default = 0;  // NOLINT
 
   // First check policy settings
-  Singleton<PolicySettings> policy;
-  PolicySettings::RendererForUrl renderer = policy->default_renderer();
+  PolicySettings::RendererForUrl renderer =
+      PolicySettings::GetInstance()->default_renderer();
   if (renderer != PolicySettings::RENDERER_NOT_SPECIFIED) {
     is_default = (renderer == PolicySettings::RENDER_IN_CHROME_FRAME);
   } else {
@@ -742,9 +742,8 @@ bool IsGcfDefaultRenderer() {
 RendererType RendererTypeForUrl(const std::wstring& url) {
   // First check if the default renderer settings are specified by policy.
   // If so, then that overrides the user settings.
-  Singleton<PolicySettings> policy;
-  PolicySettings::RendererForUrl renderer = policy->GetRendererForUrl(
-      url.c_str());
+  PolicySettings::RendererForUrl renderer =
+      PolicySettings::GetInstance()->GetRendererForUrl(url.c_str());
   if (renderer != PolicySettings::RENDERER_NOT_SPECIFIED) {
     // We may know at this point that policy says do NOT render in Chrome Frame.
     // To maintain consistency, we return RENDERER_TYPE_UNDETERMINED so that