Remove lang parameter from TextBlob alloc methods.

The 'lang' was never stored or used, so this makes no current practical
difference. The original intent was to be able to specify a language so
that it could be emitted as a 'Lang' override in the 'ActualText' when
generating a PDF. However, due to the way 'ActualText' is generally used
this would be impractical. If there is ever a desire to mark up sections
of the PDF with a specific language it would be better handled in a
different way.

Change-Id: Id63596190235fc45ce17249b9b578b6f9b838b2b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375060
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/tests/TextBlobTest.cpp b/tests/TextBlobTest.cpp
index 77cc108..f84690f 100644
--- a/tests/TextBlobTest.cpp
+++ b/tests/TextBlobTest.cpp
@@ -324,7 +324,7 @@
     (void)font.textToGlyphs(text1, strlen(text1), SkTextEncoding::kUTF8, glyphs.get(), glyphCount);
 
     auto run = SkTextBlobBuilderPriv::AllocRunText(&textBlobBuilder,
-            font, glyphCount, 0, 0, SkToInt(strlen(text2)), SkString(), nullptr);
+            font, glyphCount, 0, 0, SkToInt(strlen(text2)), nullptr);
     memcpy(run.glyphs, glyphs.get(), sizeof(uint16_t) * glyphCount);
     memcpy(run.utf8text, text2, strlen(text2));
     for (int i = 0; i < glyphCount; ++i) {