This CL add a GetInstance() method to singleton classes instead of relying on the callers to use Singleton<T>.

In some cases I have used the LazyInstance<T> pattern as that was simpler.

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.

I have selected all files under src/app and src/base which use Singleton<T> in this CL. Once this CL goes in I'll work on the rest of the files.

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

Review URL: http://codereview.chromium.org/5527004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68300 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 18 insertions, 14 deletions

diff --git a/base/time_win.cc b/base/time_win.cc
index 5d3ecd6..ca3aef1 100644
--- a/base/time_win.cc
+++ b/base/time_win.cc
@@ -310,16 +310,8 @@ TimeDelta RolloverProtectedNow() {
 // retrieve and more reliable.
 class HighResNowSingleton {
  public:
-  HighResNowSingleton()
-    : ticks_per_microsecond_(0.0),
-      skew_(0) {
-    InitializeClock();
-
-    // On Athlon X2 CPUs (e.g. model 15) QueryPerformanceCounter is
-    // unreliable.  Fallback to low-res clock.
-    base::CPU cpu;
-    if (cpu.vendor_name() == "AuthenticAMD" && cpu.family() == 15)
-      DisableHighResClock();
+  static HighResNowSingleton* GetInstance() {
+    return Singleton<HighResNowSingleton>::get();
   }
 
   bool IsUsingHighResClock() {
@@ -346,6 +338,18 @@ class HighResNowSingleton {
   }
 
  private:
+  HighResNowSingleton()
+    : ticks_per_microsecond_(0.0),
+      skew_(0) {
+    InitializeClock();
+
+    // On Athlon X2 CPUs (e.g. model 15) QueryPerformanceCounter is
+    // unreliable.  Fallback to low-res clock.
+    base::CPU cpu;
+    if (cpu.vendor_name() == "AuthenticAMD" && cpu.family() == 15)
+      DisableHighResClock();
+  }
+
   // Synchronize the QPC clock with GetSystemTimeAsFileTime.
   void InitializeClock() {
     LARGE_INTEGER ticks_per_sec = {0};
@@ -374,7 +378,7 @@ class HighResNowSingleton {
   float ticks_per_microsecond_;  // 0 indicates QPF failed and we're broken.
   int64 skew_;  // Skew between lo-res and hi-res clocks (for debugging).
 
-  DISALLOW_COPY_AND_ASSIGN(HighResNowSingleton);
+  friend struct DefaultSingletonTraits<HighResNowSingleton>;
 };
 
 }  // namespace
@@ -394,15 +398,15 @@ TimeTicks TimeTicks::Now() {
 
 // static
 TimeTicks TimeTicks::HighResNow() {
-  return TimeTicks() + Singleton<HighResNowSingleton>::get()->Now();
+  return TimeTicks() + HighResNowSingleton::GetInstance()->Now();
 }
 
 // static
 int64 TimeTicks::GetQPCDriftMicroseconds() {
-  return Singleton<HighResNowSingleton>::get()->GetQPCDriftMicroseconds();
+  return HighResNowSingleton::GetInstance()->GetQPCDriftMicroseconds();
 }
 
 // static
 bool TimeTicks::IsHighResClockWorking() {
-  return Singleton<HighResNowSingleton>::get()->IsUsingHighResClock();
+  return HighResNowSingleton::GetInstance()->IsUsingHighResClock();
 }
\ No newline at end of file