Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/platform/graphics/GraphicsContext.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 122 matching lines @@
     , m_antialiasHairlineImages(false)
 {
     // FIXME: Do some tests to determine how many states are typically used, and allocate
     // several here.
     m_paintStateStack.append(GraphicsContextState::create());
     m_paintState = m_paintStateStack.last().get();
 }
 
 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()
 {
     if (paintingDisabled())
         return;
 
     m_paintState->incrementSaveCount();
 
     m_canvasStateStack.append(CanvasSaveState(m_pendingCanvasSave, m_canvas->getSaveCount()));
@@ skipping 1727 matching lines @@
 
 void GraphicsContext::didDrawTextInRect(const SkRect& textRect)
 {
     if (m_trackTextRegion) {
         TRACE_EVENT0("skia", "PlatformContextSkia::trackTextRegion");
         m_textRegion.join(textRect);
     }
 }
 
 }