Fixing GraphicsContext state checks to support oilpan

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 104 matching lines @@
 
 GraphicsContext::GraphicsContext(SkCanvas* canvas, DisabledMode disableContextOrPainting)
     : m_canvas(canvas)
     , m_paintStateStack()
     , m_paintStateIndex(0)
     , m_pendingCanvasSave(false)
     , m_annotationMode(0)
 #if !ASSERT_DISABLED
     , m_annotationCount(0)
     , m_layerCount(0)
+    , m_saveCount(0)
+    , m_disableDestructionChecks(false)
 #endif
     , m_disabledState(disableContextOrPainting)
     , m_trackOpaqueRegion(false)
     , m_trackTextRegion(false)
     , m_useHighResMarker(false)
     , m_updatingControlTints(false)
     , m_accelerated(false)
     , m_isCertainlyOpaque(true)
     , m_printing(false)
     , m_antialiasHairlineImages(false)
 {
     if (!canvas)
         m_disabledState |= PaintingDisabled;
 
     // 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)
-    // FIXME: Oilpan: These asserts are not true for
-    // CanvasRenderingContext2D. Therefore, there is debug mode code
-    // in the CanvasRenderingContext2D that forces this to be true so
-    // that the assertions can be here for all the other cases. With
-    // Oilpan we cannot run that code in the CanvasRenderingContext2D
-    // destructor because it touches other objects that are already
-    // dead. We need to find another way of doing these asserts when
-    // Oilpan is enabled.
-    ASSERT(!m_paintStateIndex);
-    ASSERT(!m_paintState->saveCount());
-    ASSERT(!m_annotationCount);
-    ASSERT(!m_layerCount);
-    ASSERT(m_recordingStateStack.isEmpty());
+#if !ASSERT_DISABLED
+    if (!m_disableDestructionChecks) {
+        ASSERT(!m_paintStateIndex);
+        ASSERT(!m_paintState->saveCount());
+        ASSERT(!m_annotationCount);
+        ASSERT(!m_layerCount);
+        ASSERT(!m_saveCount);
+        ASSERT(m_recordingStateStack.isEmpty());
+    }
 #endif
 }
 
+void GraphicsContext::unwindStateStack()
+{
+    while (m_paintStateIndex || m_paintState->saveCount())
+        restore();

[f(malita), 2014/05/27 20:28:22]

You can probably drive this off m_canvasStateStack (less tricky):

while (!m_canvasStateStack.isEmpty())
    restore();

ASSERT(!m_paintStateIndex);
ASSERT(!m_paintState->saveCount());

+}
+
 void GraphicsContext::save()
 {
     if (contextDisabled())
         return;
 
     m_paintState->incrementSaveCount();
 
     m_canvasStateStack.append(CanvasSaveState(m_pendingCanvasSave, m_canvas->getSaveCount()));
     m_pendingCanvasSave = true;
+
+#if !ASSERT_DISABLED
+    m_saveCount++;
+#endif
 }
 
 void GraphicsContext::restore()
 {
     if (contextDisabled())
         return;
 
     if (!m_paintStateIndex && !m_paintState->saveCount()) {
         WTF_LOG_ERROR("ERROR void GraphicsContext::restore() stack is empty");
         return;
     }
 
     if (m_paintState->saveCount()) {
         m_paintState->decrementSaveCount();
     } else {
         m_paintStateIndex--;
         m_paintState = m_paintStateStack[m_paintStateIndex].get();
     }
 
     CanvasSaveState savedState = m_canvasStateStack.last();
     m_canvasStateStack.removeLast();
     m_pendingCanvasSave = savedState.m_pendingSave;
     m_canvas->restoreToCount(savedState.m_restoreCount);
+#if !ASSERT_DISABLED
+    m_saveCount--;
+#endif
 }
 
 void GraphicsContext::saveLayer(const SkRect* bounds, const SkPaint* paint)
 {
     if (contextDisabled())
         return;
 
     realizeCanvasSave();
 
     m_canvas->saveLayer(bounds, paint);
@@ skipping 1640 matching lines @@
 
 void GraphicsContext::didDrawTextInRect(const SkRect& textRect)
 {
     if (m_trackTextRegion) {
         TRACE_EVENT0("skia", "PlatformContextSkia::trackTextRegion");
         m_textRegion.join(textRect);
     }
 }
 
 }