Don't pretend we can draw MaskFilters, it produces artifacts that make the text unreadable when usi…

src/pdf/SkPDFDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPDFDevice.h"
 
 #include "SkAnnotation.h"
@@ skipping 928 matching lines @@
         return;
     }
 
     SkMatrix matrix;
     matrix.setTranslate(SkIntToScalar(x), SkIntToScalar(y));
     internalDrawBitmap(matrix, d.fClipStack, *d.fClip, bitmap, NULL, paint);
 }
 
 void SkPDFDevice::drawText(const SkDraw& d, const void* text, size_t len,
                            SkScalar x, SkScalar y, const SkPaint& paint) {
+    NOT_IMPLEMENTED(paint.getMaskFilter() != NULL, false);
+    if (paint.getMaskFilter() != NULL) {
+        // Don't pretend we support drawing MaskFilters, it makes for artifacts
+        // making text unreadable (e.g. same text twice when using CSS shadows).
+        return;
+    }
     SkPaint textPaint = calculate_text_paint(paint);
     ScopedContentEntry content(this, d, textPaint, true);
     if (!content.entry()) {
         return;
     }
 
     SkGlyphStorage storage(0);
     uint16_t* glyphIDs = NULL;
     size_t numGlyphs = force_glyph_encoding(paint, text, len, &storage,
                                             &glyphIDs);
@@ skipping 19 matching lines @@
         content.entry()->fContent.writeText(encodedString.c_str());
         consumedGlyphCount += availableGlyphs;
         content.entry()->fContent.writeText(" Tj\n");
     }
     content.entry()->fContent.writeText("ET\n");
 }
 
 void SkPDFDevice::drawPosText(const SkDraw& d, const void* text, size_t len,
                               const SkScalar pos[], SkScalar constY,
                               int scalarsPerPos, const SkPaint& paint) {
+    NOT_IMPLEMENTED(paint.getMaskFilter() != NULL, false);
+    if (paint.getMaskFilter() != NULL) {
+        // Don't pretend we support drawing MaskFilters, it makes for artifacts
+        // making text unreadable (e.g. same text twice when using CSS shadows).
+        return;
+    }
     SkASSERT(1 == scalarsPerPos || 2 == scalarsPerPos);
     SkPaint textPaint = calculate_text_paint(paint);
     ScopedContentEntry content(this, d, textPaint, true);
     if (!content.entry()) {
         return;
     }
 
     SkGlyphStorage storage(0);
     uint16_t* glyphIDs = NULL;
     size_t numGlyphs = force_glyph_encoding(paint, text, len, &storage,
@@ skipping 804 matching lines @@
 }
 
 bool SkPDFDevice::onReadPixels(const SkBitmap& bitmap, int x, int y,
                                SkCanvas::Config8888) {
     return false;
 }
 
 bool SkPDFDevice::allowImageFilter(SkImageFilter*) {
     return false;
 }