Alloc glyph image correctly for SkMask::k3D_Format.

Re-enable the code to test the emboss mask filter, updating it to use
the new emboss mask filter factory.

Add a test to ensure that embossed text is drawn correctly, as before
glyphs did not allocate the proper amount of memory for the k3D_Format
which the emboss mask filter produces.

Fixes SkEmbossMask::Emboss to write the whole of the mul and add planes
to avoid pixel differences and MemorySanitizer errors.

Update the GPU to understand the k3D_Format and use just the alpha
plane, ignoring the mul and add plane which it currently cannot support.

Change-Id: I90edf34a918c06b0c6b24bfc43ce7031419eca41
Reviewed-on: https://skia-review.googlesource.com/70260
Reviewed-on: https://skia-review.googlesource.com/70962
Reviewed-on: https://skia-review.googlesource.com/71282
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/samplecode/SampleAll.cpp b/samplecode/SampleAll.cpp
index e1b8593..ea7d508 100644
--- a/samplecode/SampleAll.cpp
+++ b/samplecode/SampleAll.cpp
@@ -208,13 +208,10 @@
         paint->setRasterizer(rastBuilder.detach());
     }
 
-#ifdef SK_SUPPORT_LEGACY_EMBOSSMASKFILTER
-    SkScalar dir[] = { SK_Scalar1, SK_Scalar1, SK_Scalar1 };
-    paint->setMaskFilter(SkBlurMaskFilter::MakeEmboss(
-                SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(3)), dir,
-                SK_Scalar1/4, SkIntToScalar(4)));
+    paint->setMaskFilter(SkEmbossMaskFilter::Make(
+                SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(3)),
+                { { SK_Scalar1, SK_Scalar1, SK_Scalar1 }, 0, 128, 16*2 }));
     paint->setColor(SK_ColorBLUE);
-#endif
 }
 
 class DemoView : public SampleView {