Fix issue incremental upload can evict textures being drawn

cc/CCPrioritizedTexture.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CCPrioritizedTexture_h
 #define CCPrioritizedTexture_h
 
 #include "base/basictypes.h"
 #include "CCPriorityCalculator.h"
 #include "CCResourceProvider.h"
@@ skipping 71 matching lines @@
 
 private:
     friend class CCPrioritizedTextureManager;
     friend class CCPrioritizedTextureTest;
 
     class Backing : public CCTexture {
     public:
         Backing(unsigned id, CCResourceProvider*, IntSize, GC3Denum format);
         ~Backing();
         void updatePriority();
+        void updateInDrawingImplTree();
 
         CCPrioritizedTexture* owner() { return m_owner; }
-        bool hadOwnerAtLastPriorityUpdate() const { return m_ownerExistedAtLastPriorityUpdate; }
+        bool canBeRecycled() const;
         int requestPriorityAtLastPriorityUpdate() const { return m_priorityAtLastPriorityUpdate; }
         bool wasAbovePriorityCutoffAtLastPriorityUpdate() const { return m_wasAbovePriorityCutoffAtLastPriorityUpdate; }
+        bool inDrawingImplTree() const { return m_inDrawingImplTree; }
 
         void deleteResource(CCResourceProvider*);
         bool resourceHasBeenDeleted() const;
 
     private:
         friend class CCPrioritizedTexture;
         CCPrioritizedTexture* m_owner;
         int m_priorityAtLastPriorityUpdate;
-        bool m_ownerExistedAtLastPriorityUpdate;
         bool m_wasAbovePriorityCutoffAtLastPriorityUpdate;
+
+        // Set if this is currently-drawing impl tree.
+        bool m_inDrawingImplTree;
+
         bool m_resourceHasBeenDeleted;
 #ifndef NDEBUG
         CCResourceProvider* m_resourceProvider;
 #endif
 
         DISALLOW_COPY_AND_ASSIGN(Backing);
     };
 
     CCPrioritizedTexture(CCPrioritizedTextureManager*, IntSize, GC3Denum format);
 
@@ skipping 15 matching lines @@
 
     Backing* m_backing;
     CCPrioritizedTextureManager* m_manager;
 
     DISALLOW_COPY_AND_ASSIGN(CCPrioritizedTexture);
 };
 
 }  // namespace cc
 
 #endif