service/device: Add wake locks that allow screen dimming.

Add WakeLockType::PreventDisplaySleepAllowDimming to the
device service's WakeLock mojo interface. A similar level is
currently exposed by chromeos::PowerPolicyController and
used by ARC. This type is treated identically to
PreventDisplaySleep on non-Chrome-OS platforms.

Bug: 702449
Change-Id: I9810fa69c8472a264a067d34ee92cef0125d41e5
Reviewed-on: https://chromium-review.googlesource.com/749342Reviewed-by: Greg Kerr <kerrnel@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Commit-Queue: Dan Erat <derat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513292}

extensions/browser/api/power/power_api_unittest.cc

@@ -87,6 +87,9 @@ class FakeWakeLockManager {
           requests_.push_back(BLOCK_DISPLAY_SLEEP);
           requests_.push_back(UNBLOCK_APP_SUSPENSION);
           break;
+        case device::mojom::WakeLockType::PreventDisplaySleepAllowDimming:
+          NOTREACHED() << "Unexpected wake lock type " << type;
+          break;
       }
 
       type_ = type;
@@ -102,6 +105,9 @@ class FakeWakeLockManager {
         case device::mojom::WakeLockType::PreventDisplaySleep:
           requests_.push_back(BLOCK_DISPLAY_SLEEP);
           break;
+        case device::mojom::WakeLockType::PreventDisplaySleepAllowDimming:
+          NOTREACHED() << "Unexpected wake lock type " << type;
+          break;
       }
 
       type_ = type;
@@ -119,6 +125,9 @@ class FakeWakeLockManager {
       case device::mojom::WakeLockType::PreventDisplaySleep:
         requests_.push_back(UNBLOCK_DISPLAY_SLEEP);
         break;
+      case device::mojom::WakeLockType::PreventDisplaySleepAllowDimming:
+        NOTREACHED() << "Unexpected wake lock type " << type_;
+        break;
     }
     is_active_ = false;
   }

services/device/public/interfaces/wake_lock.mojom

@@ -17,6 +17,11 @@ enum WakeLockType {
     // app from being suspended on some platforms if the user hides it.
     // Example use case: playing video.
     PreventDisplaySleep = 1,
+
+    // Like PreventDisplaySleep, but permits the display to dim while remaining
+    // on. On some platforms, this may be treated identically to
+    // PreventDisplaySleep.
+    PreventDisplaySleepAllowDimming = 2,
 };
 
 enum WakeLockReason {

services/device/wake_lock/power_save_blocker/power_save_blocker.h

@@ -36,6 +36,11 @@ class PowerSaveBlocker {
     // app from being suspended on some platforms if the user hides it.
     // Example use case: playing video.
     kPowerSaveBlockPreventDisplaySleep,
+
+    // Like kPowerSaveBlockPreventDisplaySleep, but permits the display to dim
+    // while remaining on. On some platforms, this may be treated identically to
+    // kPowerSaveBlockPreventDisplaySleep.
+    kPowerSaveBlockPreventDisplaySleepAllowDimming,
   };
 
   // Reasons why power-saving features may be blocked.

services/device/wake_lock/power_save_blocker/power_save_blocker_chromeos.cc

@@ -63,6 +63,10 @@ class PowerSaveBlocker::Delegate
         block_id_ = controller->AddScreenWakeLock(GetWakeLockReason(reason_),
                                                   description_);
         break;
+      case kPowerSaveBlockPreventDisplaySleepAllowDimming:
+        block_id_ = controller->AddDimWakeLock(GetWakeLockReason(reason_),
+                                               description_);
+        break;
       default:
         NOTREACHED() << "Unhandled block type " << type_;
     }

services/device/wake_lock/power_save_blocker/power_save_blocker_mac.cc

@@ -73,6 +73,7 @@ void PowerSaveBlocker::Delegate::ApplyBlock() {
       level = kIOPMAssertionTypeNoIdleSleep;
       break;
     case PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep:
+    case PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleepAllowDimming:
       level = kIOPMAssertionTypeNoDisplaySleep;
       break;
     default:

services/device/wake_lock/power_save_blocker/power_save_blocker_win.cc

@@ -99,7 +99,8 @@ void PowerSaveBlocker::Delegate::RemoveBlock() {
 }
 
 POWER_REQUEST_TYPE PowerSaveBlocker::Delegate::RequestType() {
-  if (type_ == kPowerSaveBlockPreventDisplaySleep)
+  if (type_ == kPowerSaveBlockPreventDisplaySleep ||
+      type_ == kPowerSaveBlockPreventDisplaySleepAllowDimming)
     return PowerRequestDisplayRequired;
 
   if (base::win::GetVersion() == base::win::VERSION_WIN7)

services/device/wake_lock/power_save_blocker/power_save_blocker_x11.cc

@@ -276,6 +276,7 @@ void PowerSaveBlocker::Delegate::ApplyBlock() {
         uint32_t flags = 0;
         switch (type_) {
           case kPowerSaveBlockPreventDisplaySleep:
+          case kPowerSaveBlockPreventDisplaySleepAllowDimming:
             flags |= INHIBIT_MARK_SESSION_IDLE;
             flags |= INHIBIT_SUSPEND_SESSION;
             break;
@@ -289,6 +290,7 @@ void PowerSaveBlocker::Delegate::ApplyBlock() {
     case FREEDESKTOP_API:
       switch (type_) {
         case kPowerSaveBlockPreventDisplaySleep:
+        case kPowerSaveBlockPreventDisplaySleepAllowDimming:
           object_proxy = bus_->GetObjectProxy(
               kFreeDesktopAPIScreenServiceName,
               dbus::ObjectPath(kFreeDesktopAPIScreenObjectPath));
@@ -374,6 +376,7 @@ void PowerSaveBlocker::Delegate::RemoveBlock() {
     case FREEDESKTOP_API:
       switch (type_) {
         case kPowerSaveBlockPreventDisplaySleep:
+        case kPowerSaveBlockPreventDisplaySleepAllowDimming:
           object_proxy = bus_->GetObjectProxy(
               kFreeDesktopAPIScreenServiceName,
               dbus::ObjectPath(kFreeDesktopAPIScreenObjectPath));
@@ -497,7 +500,8 @@ PowerSaveBlocker::PowerSaveBlocker(
       blocking_task_runner_(blocking_task_runner) {
   delegate_->Init();
 
-  if (type == kPowerSaveBlockPreventDisplaySleep) {
+  if (type == kPowerSaveBlockPreventDisplaySleep ||
+      type == kPowerSaveBlockPreventDisplaySleepAllowDimming) {
     freedesktop_suspend_delegate_ = new Delegate(
         kPowerSaveBlockPreventAppSuspension, description,
         true /* freedesktop_only */, ui_task_runner, blocking_task_runner);

services/device/wake_lock/wake_lock.cc

@@ -21,6 +21,9 @@ PowerSaveBlocker::PowerSaveBlockerType ToPowerSaveBlockerType(
     case mojom::WakeLockType::PreventDisplaySleep:
       return PowerSaveBlocker::PowerSaveBlockerType::
           kPowerSaveBlockPreventDisplaySleep;
+    case mojom::WakeLockType::PreventDisplaySleepAllowDimming:
+      return PowerSaveBlocker::PowerSaveBlockerType::
+          kPowerSaveBlockPreventDisplaySleepAllowDimming;
   }
 
   NOTREACHED();

services/device/wake_lock/wake_lock_unittest.cc

@@ -121,6 +121,8 @@ TEST_F(WakeLockTest, ChangeType) {
   // Call ChangeType() on a wake lock that is in inactive status.
   EXPECT_TRUE(ChangeType(device::mojom::WakeLockType::PreventAppSuspension));
   EXPECT_TRUE(ChangeType(device::mojom::WakeLockType::PreventDisplaySleep));
+  EXPECT_TRUE(
+      ChangeType(device::mojom::WakeLockType::PreventDisplaySleepAllowDimming));
   EXPECT_FALSE(HasWakeLock());  // still inactive.
 
   wake_lock_->RequestWakeLock();
@@ -128,6 +130,8 @@ TEST_F(WakeLockTest, ChangeType) {
   // Call ChangeType() on a wake lock that is in active status.
   EXPECT_TRUE(ChangeType(device::mojom::WakeLockType::PreventAppSuspension));
   EXPECT_TRUE(ChangeType(device::mojom::WakeLockType::PreventDisplaySleep));
+  EXPECT_TRUE(
+      ChangeType(device::mojom::WakeLockType::PreventDisplaySleepAllowDimming));
   EXPECT_TRUE(HasWakeLock());  // still active.
 
   // Send multiple requests, should be coalesced as usual.
@@ -145,6 +149,8 @@ TEST_F(WakeLockTest, ChangeType) {
 #else  // OS_ANDROID:
   EXPECT_FALSE(ChangeType(device::mojom::WakeLockType::PreventAppSuspension));
   EXPECT_FALSE(ChangeType(device::mojom::WakeLockType::PreventDisplaySleep));
+  EXPECT_FALSE(
+      ChangeType(device::mojom::WakeLockType::PreventDisplaySleepAllowDimming));
 #endif
 }