SkTextBlob GPipe serialization.

Instead of relying on unrolling blobs in SkCanvas, serialize when
passing through a GPipe.

This is a prerequisite for pushing the blob draw op to the device.

R=mtklein@google.com, reed@google.com, robertphillips@google.com

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/511783005
diff --git a/src/pipe/SkGPipeRead.cpp b/src/pipe/SkGPipeRead.cpp
index e48baf3..4bd4fa6 100644
--- a/src/pipe/SkGPipeRead.cpp
+++ b/src/pipe/SkGPipeRead.cpp
@@ -26,6 +26,7 @@
 #include "SkRasterizer.h"
 #include "SkRRect.h"
 #include "SkShader.h"
+#include "SkTextBlob.h"
 #include "SkTypeface.h"
 #include "SkXfermode.h"
 
@@ -672,7 +673,19 @@
 
 static void drawTextBlob_rp(SkCanvas* canvas, SkReader32* reader, uint32_t op32,
                             SkGPipeState* state) {
-    UNIMPLEMENTED
+    SkScalar x = reader->readScalar();
+    SkScalar y = reader->readScalar();
+
+    size_t blobSize = reader->readU32();
+    const void* data = reader->skip(SkAlign4(blobSize));
+
+    if (state->shouldDraw()) {
+        SkReadBuffer blobBuffer(data, blobSize);
+        SkAutoTUnref<const SkTextBlob> blob(SkTextBlob::CreateFromBuffer(blobBuffer));
+        SkASSERT(blob.get());
+
+        canvas->drawTextBlob(blob, x, y, state->paint());
+    }
 }
 ///////////////////////////////////////////////////////////////////////////////