Test abandoning GL context in dm/nanobench.

include/gpu/GrContextFactory.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrContextFactory_DEFINED
 #define GrContextFactory_DEFINED
 
@@ skipping 76 matching lines @@
                 SkFAIL("Unknown GL Context type.");
         }
     }
 
     GrContextFactory() { }
 
     ~GrContextFactory() { this->destroyContexts(); }
 
     void destroyContexts() {
         for (int i = 0; i < fContexts.count(); ++i) {
-            fContexts[i].fGLContext->makeCurrent();
+            if (NULL != fContexts[i].fGLContext) {  //  could be abandoned.
+                fContexts[i].fGLContext->makeCurrent();
+            }
             fContexts[i].fGrContext->unref();
-            fContexts[i].fGLContext->unref();
+            if (NULL != fContexts[i].fGLContext) {
+                fContexts[i].fGLContext->unref();
+            }
         }
         fContexts.reset();
     }
 
+    void abandonContexts() {
+        for (int i = 0; i < fContexts.count(); ++i) {
+            SkSafeSetNull(fContexts[i].fGLContext);
+            fContexts[i].fGrContext->abandonContext();
+        }
+    }
+
     /**
      * Get a GrContext initialized with a type of GL context. It also makes the GL context current.
      */
     GrContext* get(GLContextType type, GrGLStandard forcedGpuAPI = kNone_GrGLStandard) {
         for (int i = 0; i < fContexts.count(); ++i) {
             if (forcedGpuAPI != kNone_GrGLStandard &&
                 forcedGpuAPI != fContexts[i].fGLContext->gl()->fStandard)
                 continue;
 
             if (fContexts[i].fType == type) {
@@ skipping 76 matching lines @@
 private:
     struct GPUContext {
         GLContextType             fType;
         SkGLContextHelper*        fGLContext;
         GrContext*                fGrContext;
     };
     SkTArray<GPUContext, true> fContexts;
 };
 
 #endif