Add debug option to clip each GrBatch to its device bounds

dm/DMGpuSupport.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef DMGpuSupport_DEFINED
 #define DMGpuSupport_DEFINED
 
@@ skipping 39 matching lines @@
 static const int kGrGLStandardCnt = 3;
 
 class GrContext {
 public:
     void dumpCacheStats(SkString*) const {}
     void dumpGpuStats(SkString*) const {}
 };
 
 struct GrContextOptions {
     bool fImmediateMode;
+    bool fClipBatchToBounds;
 };
 
 class GrContextFactory {
 public:
     GrContextFactory() {};
     explicit GrContextFactory(const GrContextOptions&) {}
 
     typedef int GLContextType;
 
     static const GLContextType kANGLE_GLContextType         = 0,
@@ skipping 21 matching lines @@
                                        int,
                                        bool) {
     return nullptr;
 }
 
 }  // namespace DM
 
 #endif//SK_SUPPORT_GPU
 
 #endif//DMGpuSupport_DEFINED