Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/platform/graphics/GraphicsContext.cpp

Index: Source/platform/graphics/GraphicsContext.cpp
diff --git a/Source/platform/graphics/GraphicsContext.cpp b/Source/platform/graphics/GraphicsContext.cpp
index e2b091292f892a9b8631b9a334c861099df9771b..5c60a10c1674215daa7e0ea05bdea4eaad253216 100644
--- a/Source/platform/graphics/GraphicsContext.cpp
+++ b/Source/platform/graphics/GraphicsContext.cpp
@@ -140,11 +140,18 @@ GraphicsContext::GraphicsContext(SkCanvas* canvas)
 
 GraphicsContext::~GraphicsContext()
 {
+#if !ENABLE(OILPAN)
+    // These asserts are only valid in debug mode and therefore do not seem
+    // useful. We cannot rely on them in any case. With Oilpan we cannot run

[haraken, 2014/04/24 04:18:43]

Nit: I'd drop the first two sentences. These asserts would be here because it's
useful to check something in non-oilpan builds. If you're sure that they are not
useful, you can just remove the asserts.

[Mads Ager (chromium), 2014/04/24 10:57:36]

I do want the first two sentences here. This code is extremely weird. There is
special code in debug-mode that makes sure that these ASSERTS hold. However,
that means that this is not actually true in the release builds. Therefore,
having asserts here at all is really weird. When you see an assert in the code
you expect what the assert is saying to be true of the system (both release and
debug mode). Having an assert that checks that you have done something only in
debug mode is confusing and misleading. However, I don't want to remove these
from the non-oilpan code base without talking to someone about it first. In
other words, not for this changelist.

+    // the debug mode only code in CanvasRendingContext2D's destructor which

[haraken, 2014/04/24 04:18:43]

we cannot run CanvasRendingContext2D's destructor which ...

[Mads Ager (chromium), 2014/04/24 10:57:36]

We can run the destructor. But we cannot run the debug mode only code in it.

+    // touches other objects that are dead. Therefore, we disable these asserts
+    // with Oilpan and should probably consider just disabling them.
     ASSERT(!m_paintStateIndex);
     ASSERT(!m_paintState->saveCount());
     ASSERT(!m_annotationCount);
     ASSERT(!m_layerCount);
     ASSERT(m_recordingStateStack.isEmpty());
+#endif
 }
 
 void GraphicsContext::save()