Revert of Consolidate GPU buffer implementations

include/gpu/GrContextOptions.h

Index: include/gpu/GrContextOptions.h
diff --git a/include/gpu/GrContextOptions.h b/include/gpu/GrContextOptions.h
index 4e763405e103c1e9211bf37e2af04e98d2d62bdb..d7070db555a567c2f93b31b51044f4a4af074ebb 100644
--- a/include/gpu/GrContextOptions.h
+++ b/include/gpu/GrContextOptions.h
@@ -17,7 +17,7 @@
         , fMaxTextureSizeOverride(SK_MaxS32)
         , fMaxTileSizeOverride(0)
         , fSuppressDualSourceBlending(false)
-        , fBufferMapThreshold(-1)
+        , fGeometryBufferMapThreshold(-1)
         , fUseDrawInsteadOfPartialRenderTargetWrite(false)
         , fImmediateMode(false)
         , fClipBatchToBounds(false)
@@ -47,7 +47,7 @@
     /** the threshold in bytes above which we will use a buffer mapping API to map vertex and index
         buffers to CPU memory in order to update them.  A value of -1 means the GrContext should
         deduce the optimal value for this platform. */
-    int  fBufferMapThreshold;
+    int  fGeometryBufferMapThreshold;
 
     /** some gpus have problems with partial writes of the rendertarget */
     bool fUseDrawInsteadOfPartialRenderTargetWrite;