Add support for glMapBufferRange. Use glMapBufferRange and glMapBufferSubData.

BUG=skia:2402

Committed: http://code.google.com/p/skia/source/detail?r=14533

R=robertphillips@google.com, djsollen@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/243413002

git-svn-id: http://skia.googlecode.com/svn/trunk@14564 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/gl/GrGLInterface.h b/include/gpu/gl/GrGLInterface.h
index 9070af2..2b33e8e 100644
--- a/include/gpu/gl/GrGLInterface.h
+++ b/include/gpu/gl/GrGLInterface.h
@@ -192,6 +192,7 @@
         GLPtr<GrGLEndQueryProc> fEndQuery;
         GLPtr<GrGLFinishProc> fFinish;
         GLPtr<GrGLFlushProc> fFlush;
+        GLPtr<GrGLFlushMappedBufferRangeProc> fFlushMappedBufferRange;
         GLPtr<GrGLFramebufferRenderbufferProc> fFramebufferRenderbuffer;
         GLPtr<GrGLFramebufferTexture2DProc> fFramebufferTexture2D;
         GLPtr<GrGLFramebufferTexture2DMultisampleProc> fFramebufferTexture2DMultisample;
@@ -231,6 +232,7 @@
         GLPtr<GrGLLineWidthProc> fLineWidth;
         GLPtr<GrGLLinkProgramProc> fLinkProgram;
         GLPtr<GrGLMapBufferProc> fMapBuffer;
+        GLPtr<GrGLMapBufferRangeProc> fMapBufferRange;
         GLPtr<GrGLMapBufferSubDataProc> fMapBufferSubData;
         GLPtr<GrGLMapTexSubImage2DProc> fMapTexSubImage2D;
         GLPtr<GrGLMatrixLoadfProc> fMatrixLoadf;