small fix for clip mask cache clear

src/gpu/GrGpu.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGpu_DEFINED
 #define GrGpu_DEFINED
 
@@ skipping 257 matching lines @@
     // GrDrawTarget overrides
     virtual void clear(const SkIRect* rect,
                        GrColor color,
                        bool canIgnoreRect,
                        GrRenderTarget* renderTarget = NULL) SK_OVERRIDE;
 
     virtual void clearStencilClip(const SkIRect& rect,
                                   bool insideClip,
                                   GrRenderTarget* renderTarget = NULL) SK_OVERRIDE;
 
-    virtual void purgeResources() SK_OVERRIDE {
-        // The clip mask manager can rebuild all its clip masks so just
-        // get rid of them all.
-        fClipMaskManager.purgeResources();
-    }
-
     // After the client interacts directly with the 3D context state the GrGpu
     // must resync its internal state and assumptions about 3D context state.
     // Each time this occurs the GrGpu bumps a timestamp.
     // state of the 3D context
     // At 10 resets / frame and 60fps a 64bit timestamp will overflow in about
     // a billion years.
     typedef uint64_t ResetTimestamp;
 
     // This timestamp is always older than the current timestamp
     static const ResetTimestamp kExpiredTimestamp = 0;
@@ skipping 170 matching lines @@
     virtual void onDrawPaths(const GrPathRange*,
                              const uint32_t indices[], int count,
                              const float transforms[], PathTransformType,
                              SkPath::FillType, const GrDeviceCoordTexture*) SK_OVERRIDE;
 
     // readies the pools to provide vertex/index data.
     void prepareVertexPool();
     void prepareIndexPool();
 
     void resetContext() {
-        // We call this because the client may have messed with the
-        // stencil buffer. Perhaps we should detect whether it is a
-        // internally created stencil buffer and if so skip the invalidate.
-        fClipMaskManager.invalidateStencilMask();
         this->onResetContext(fResetBits);
         fResetBits = 0;
         ++fResetTimestamp;
     }
 
     void handleDirtyContext() {
         if (fResetBits) {
             this->resetContext();
         }
     }
 
     enum {
         kPreallocGeomPoolStateStackCnt = 4,
     };
     SkSTArray<kPreallocGeomPoolStateStackCnt, GeometryPoolState, true>  fGeomPoolStateStack;
     ResetTimestamp                                                      fResetTimestamp;
     uint32_t                                                            fResetBits;
     GrVertexBufferAllocPool*                                            fVertexPool;
     GrIndexBufferAllocPool*                                             fIndexPool;
     // counts number of uses of vertex/index pool in the geometry stack
     int                                                                 fVertexPoolUseCnt;
     int                                                                 fIndexPoolUseCnt;
     // these are mutable so they can be created on-demand
     mutable GrIndexBuffer*                                              fQuadIndexBuffer;
 
     typedef GrClipTarget INHERITED;
 };
 
 #endif