Loosen requirement that there be only one GrDrawTarget

include/gpu/GrContext.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 170 matching lines @@
      * @return a draw context
      */
     GrDrawContext* drawContext(GrRenderTarget* rt, const SkSurfaceProps* surfaceProps = NULL) {
         return fDrawingMgr.drawContext(rt, surfaceProps);
     }
 
     GrTextContext* textContext(const SkSurfaceProps& surfaceProps, GrRenderTarget* rt) {
         return fDrawingMgr.textContext(surfaceProps, rt);
     }
 
+    // The caller automatically gets a ref on the returned drawTarget. It must 
+    // be balanced by an unref call.
+    GrDrawTarget* newDrawTarget(GrRenderTarget* rt) {
+        return fDrawingMgr.newDrawTarget(rt);
+    }
+
     ///////////////////////////////////////////////////////////////////////////
     // Misc.
 
     /**
      * Flags that affect flush() behavior.
      */
     enum FlushBits {
         /**
          * A client may reach a point where it has partially rendered a frame
          * through a GrContext that it knows the user will never see. This flag
@@ skipping 218 matching lines @@
     // combination of text drawing options (pixel geometry x DFT use)
     // and hands the appropriate one back given the DrawContext's request.
     //
     // It allocates a new GrDrawContext for each GrRenderTarget
     // but all of them still land in the same GrDrawTarget!
     //
     // In the future this class will allocate a new GrDrawContext for
     // each GrRenderTarget/GrDrawTarget and manage the DAG.
     class DrawingMgr {
     public:
-        DrawingMgr() : fDrawTarget(nullptr), fNVPRTextContext(nullptr) {
+        DrawingMgr()
+            : fContext(nullptr)
+            , fAbandoned(false)
+            , fNVPRTextContext(nullptr) {
             sk_bzero(fTextContexts, sizeof(fTextContexts));
         }
 
         ~DrawingMgr();
 
         void init(GrContext* context);
 
         void abandon();
-        bool abandoned() const { return NULL == fDrawTarget; }
+        bool abandoned() const { return fAbandoned; }
 
         void reset();
         void flush();
 
         // Callers assume the creation ref of the drawContext!
         // NULL will be returned if the context has been abandoned.
         GrDrawContext* drawContext(GrRenderTarget* rt, const SkSurfaceProps* surfaceProps);
 
         GrTextContext* textContext(const SkSurfaceProps& props, GrRenderTarget* rt);
+        
+        GrDrawTarget* newDrawTarget(GrRenderTarget* rt);
 
     private:
         void cleanup();
 
         friend class GrContext;  // for access to fDrawTarget for testing
 
         static const int kNumPixelGeometries = 5; // The different pixel geometries
         static const int kNumDFTOptions = 2;      // DFT or no DFT
 
         GrContext*        fContext;
-        GrDrawTarget*     fDrawTarget;
+
+        bool              fAbandoned;
+        SkTDArray<GrDrawTarget*> fDrawTargets;
 
         GrTextContext*    fNVPRTextContext;
         GrTextContext*    fTextContexts[kNumPixelGeometries][kNumDFTOptions];
     };
 
     DrawingMgr                      fDrawingMgr;
 
     void initMockContext();
     void initCommon();
 
@@ skipping 23 matching lines @@
     /**
      * A callback similar to the above for use by the TextBlobCache
      * TODO move textblob draw calls below context so we can use the call above.
      */
     static void TextBlobCacheOverBudgetCB(void* data);
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif