Remove SK_SUPPORT_LEGACY_TEXT_BLOB

Removing this flag will allow skia to process text blobs
using the new glyph run code.

TBR=

Change-Id: Ib834240778121f628ac2b966211703e7a69588ef
Reviewed-on: https://chromium-review.googlesource.com/1153449Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578852}

skia/config/SkUserConfig.h

@@ -173,11 +173,6 @@ SK_API void SkDebugf_FileLine(const char* file, int line, bool fatal,
 #define SK_IGNORE_MATRIX_IMAGE_FILTER_FIX
 #endif
 
-// convert from text blob to glyph run
-#ifndef SK_SUPPORT_LEGACY_TEXT_BLOB
-#define SK_SUPPORT_LEGACY_TEXT_BLOB
-#endif
-
 // remove after rebaselining svg layout tests
 #ifndef SK_SUPPORT_LEGACY_SVG_ARC_TO
 #define SK_SUPPORT_LEGACY_SVG_ARC_TO