Move PlatformEventDispatcher implementations to the Oilpan heap.

Source/modules/device_light/DeviceLightDispatcher.cpp

Index: Source/modules/device_light/DeviceLightDispatcher.cpp
diff --git a/Source/modules/device_light/DeviceLightDispatcher.cpp b/Source/modules/device_light/DeviceLightDispatcher.cpp
index d56a0a03d95d705c0a6e799d277596521f511f88..eda852be5a35daa151c0155443f6f2f5009d7737 100644
--- a/Source/modules/device_light/DeviceLightDispatcher.cpp
+++ b/Source/modules/device_light/DeviceLightDispatcher.cpp
@@ -12,8 +12,8 @@ namespace blink {
 
 DeviceLightDispatcher& DeviceLightDispatcher::instance()
 {
-    DEFINE_STATIC_LOCAL(DeviceLightDispatcher, deviceLightDispatcher, ());
-    return deviceLightDispatcher;
+    DEFINE_STATIC_LOCAL(OwnPtrWillBePersistent<DeviceLightDispatcher>, deviceLightDispatcher, (adoptPtrWillBeNoop(new DeviceLightDispatcher())));

[haraken, 2014/10/03 13:18:17]

I still don't understand why this isn't Persistent<DeviceLightDispatcher>.

OwnPtr<DeviceLightDispatcher> should cause a compile error, I guess.

[sof, 2014/10/03 13:33:58]

Ouch, there should be no use of OwnPtr<> here. Fixed, thanks for catching that.

adoptPtr() takes a bare pointer, so that won't elicit a complaint.

[haraken, 2014/10/03 14:15:07]

Ideally we want to insert an assert to adoptPtr() and verify that adoptPtr()
does not adopt GarbageCollected objects. Previously we tried to insert the
assert but we failed, because the assert requires to violate our directory
dependency rules (wtf/ cannot depend on platform/heap or something like that). I
forgot the exact reason why we couldn't. It might be worth revisiting the issue.

+    return *deviceLightDispatcher;
 }
 
 DeviceLightDispatcher::DeviceLightDispatcher()
@@ -25,6 +25,11 @@ DeviceLightDispatcher::~DeviceLightDispatcher()
 {
 }
 
+void DeviceLightDispatcher::trace(Visitor* visitor)
+{
+    PlatformEventDispatcher::trace(visitor);
+}
+
 void DeviceLightDispatcher::startListening()
 {
     Platform::current()->startListening(WebPlatformEventDeviceLight, this);