Use PowerSaveBlocker for audio and video on Chrome OS.

content/browser/power_save_blocker_win.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/power_save_blocker_impl.h"
 
 #include <windows.h>
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/scoped_handle.h"
 #include "base/win/windows_version.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 namespace {
 
 int g_blocker_count[2];
 
-HANDLE CreatePowerRequest(POWER_REQUEST_TYPE type, const std::string& reason) {
+HANDLE CreatePowerRequest(POWER_REQUEST_TYPE type,
+                          const std::string& description) {
   typedef HANDLE (WINAPI* PowerCreateRequestPtr)(PREASON_CONTEXT);
   typedef BOOL (WINAPI* PowerSetRequestPtr)(HANDLE, POWER_REQUEST_TYPE);
 
   if (type == PowerRequestExecutionRequired &&
       base::win::GetVersion() < base::win::VERSION_WIN8) {
     return INVALID_HANDLE_VALUE;
   }
 
   static PowerCreateRequestPtr PowerCreateRequestFn = NULL;
   static PowerSetRequestPtr PowerSetRequestFn = NULL;
 
   if (!PowerCreateRequestFn || !PowerSetRequestFn) {
     HMODULE module = GetModuleHandle(L"kernel32.dll");
     PowerCreateRequestFn = reinterpret_cast<PowerCreateRequestPtr>(
         GetProcAddress(module, "PowerCreateRequest"));
     PowerSetRequestFn = reinterpret_cast<PowerSetRequestPtr>(
         GetProcAddress(module, "PowerSetRequest"));
 
     if (!PowerCreateRequestFn || !PowerSetRequestFn)
       return INVALID_HANDLE_VALUE;
   }
-  base::string16 wide_reason = base::ASCIIToUTF16(reason);
+  base::string16 wide_description = base::ASCIIToUTF16(description);
   REASON_CONTEXT context = {0};
   context.Version = POWER_REQUEST_CONTEXT_VERSION;
   context.Flags = POWER_REQUEST_CONTEXT_SIMPLE_STRING;
-  context.Reason.SimpleReasonString = const_cast<wchar_t*>(wide_reason.c_str());
+  context.Reason.SimpleReasonString =
+      const_cast<wchar_t*>(wide_description.c_str());
 
   base::win::ScopedHandle handle(PowerCreateRequestFn(&context));
   if (!handle.IsValid())
     return INVALID_HANDLE_VALUE;
 
   if (PowerSetRequestFn(handle.Get(), type))
     return handle.Take();
 
   // Something went wrong.
   return INVALID_HANDLE_VALUE;
@@ skipping 46 matching lines @@
     flags |= this_flag;
 
   SetThreadExecutionState(flags);
 }
 
 }  // namespace
 
 class PowerSaveBlockerImpl::Delegate
     : public base::RefCountedThreadSafe<PowerSaveBlockerImpl::Delegate> {
  public:
-  Delegate(PowerSaveBlockerType type, const std::string& reason)
-      : type_(type), reason_(reason) {}
+  Delegate(PowerSaveBlockerType type, const std::string& description)
+      : type_(type), description_(description) {}
 
   // Does the actual work to apply or remove the desired power save block.
   void ApplyBlock();
   void RemoveBlock();
 
   // Returns the equivalent POWER_REQUEST_TYPE for this request.
   POWER_REQUEST_TYPE RequestType();
 
  private:
   friend class base::RefCountedThreadSafe<Delegate>;
   ~Delegate() {}
 
   PowerSaveBlockerType type_;
-  const std::string reason_;
+  const std::string description_;
   base::win::ScopedHandle handle_;
 
   DISALLOW_COPY_AND_ASSIGN(Delegate);
 };
 
 void PowerSaveBlockerImpl::Delegate::ApplyBlock() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (base::win::GetVersion() < base::win::VERSION_WIN7)
     return ApplySimpleBlock(type_, 1);
 
-  handle_.Set(CreatePowerRequest(RequestType(), reason_));
+  handle_.Set(CreatePowerRequest(RequestType(), description_));
 }
 
 void PowerSaveBlockerImpl::Delegate::RemoveBlock() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (base::win::GetVersion() < base::win::VERSION_WIN7)
     return ApplySimpleBlock(type_, -1);
 
   DeletePowerRequest(RequestType(), handle_.Take());
 }
 
 POWER_REQUEST_TYPE PowerSaveBlockerImpl::Delegate::RequestType() {
   if (type_ == kPowerSaveBlockPreventDisplaySleep)
     return PowerRequestDisplayRequired;
 
   if (base::win::GetVersion() < base::win::VERSION_WIN8)
     return PowerRequestSystemRequired;
 
   return PowerRequestExecutionRequired;
 }
 
 PowerSaveBlockerImpl::PowerSaveBlockerImpl(PowerSaveBlockerType type,
-                                           const std::string& reason)
-    : delegate_(new Delegate(type, reason)) {
+                                           Reason reason,
+                                           const std::string& description)
+    : delegate_(new Delegate(type, description)) {
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&Delegate::ApplyBlock, delegate_));
 }
 
 PowerSaveBlockerImpl::~PowerSaveBlockerImpl() {
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&Delegate::RemoveBlock, delegate_));
 }
 
 }  // namespace content