Content: fix the power save blocker for Win7.

content/browser/power_save_blocker_win.cc

Index: content/browser/power_save_blocker_win.cc
===================================================================
--- content/browser/power_save_blocker_win.cc	(revision 140668)
+++ content/browser/power_save_blocker_win.cc	(working copy)
@@ -165,8 +165,7 @@
 
 void PowerSaveBlocker::Delegate::ApplyBlock() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  base::win::Version os_version = base::win::GetVersion();
-  if (os_version < base::win::VERSION_WIN7)
+  if (base::win::GetVersion() < base::win::VERSION_WIN7)
     return ApplySimpleBlock(type_, 1);
 
   handle_.Set(CreatePowerRequest(RequestType(), reason_));
@@ -174,8 +173,7 @@
 
 void PowerSaveBlocker::Delegate::RemoveBlock() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  base::win::Version os_version = base::win::GetVersion();
-  if (os_version < base::win::VERSION_WIN7)
+  if (base::win::GetVersion() < base::win::VERSION_WIN7)
     return ApplySimpleBlock(type_, -1);
 
   DeletePowerRequest(RequestType(), handle_.Take());
@@ -185,6 +183,9 @@
   if (type_ == kPowerSaveBlockPreventDisplaySleep)
     return PowerRequestDisplayRequired;
 
+  if (base::win::GetVersion() < base::win::VERSION_WIN8)
+    return PowerRequestSystemRequired;
+
   return PowerRequestExecutionRequired;
 }