Add support for GL_ANGLE_pack_reverse_row_order

Review URL: http://codereview.appspot.com/5448063/


git-svn-id: http://skia.googlecode.com/svn/trunk@2774 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/GrGLConfig_chrome.h b/include/gpu/GrGLConfig_chrome.h
index 72d330a..ee3c991 100644
--- a/include/gpu/GrGLConfig_chrome.h
+++ b/include/gpu/GrGLConfig_chrome.h
@@ -17,6 +17,9 @@
 // For RGBA teximage/readpixels ANGLE will sw-convert to/from BGRA.
 #define GR_GL_RGBA_8888_PIXEL_OPS_SLOW  GR_WIN32_BUILD
 
+// ANGLE can go faster if the entire fbo is read rather than a subrect
+#define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL GR_WIN32_BUILD
+
 // cmd buffer allocates memory and memsets it to zero when it sees glBufferData
 // with NULL.
 #define GR_GL_USE_BUFFER_DATA_NULL_HINT 0