Add glReadBuffer to GrGLInterface.

Review URL: http://codereview.appspot.com/4841048/





git-svn-id: http://skia.googlecode.com/svn/trunk@2034 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/android/GrGLDefaultInterface_android.cpp b/gpu/src/android/GrGLDefaultInterface_android.cpp
index b402176..033a93c 100644
--- a/gpu/src/android/GrGLDefaultInterface_android.cpp
+++ b/gpu/src/android/GrGLDefaultInterface_android.cpp
@@ -77,6 +77,7 @@
     NULL,  // glMatrixMode
     glPixelStorei,
     NULL,  // glPointSize
+    NULL, // glReadBuffer
     glReadPixels,
     glScissor,
     NULL,  // glShadeModel