misc fixes to make float buffers work a little better

src/core/SkBlitter.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBlitter.h"
 #include "SkAntiRun.h"
 #include "SkColor.h"
@@ skipping 109 matching lines @@
 }
 
 // maskBitCount is the number of 1's to place in the mask. It must be in the range between 1 and 8.
 static uint8_t generate_right_mask(int maskBitCount) {
     return static_cast<uint8_t>(0xFF00U >> maskBitCount);
 }
 
 void SkBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
     SkASSERT(mask.fBounds.contains(clip));
 
+    if (mask.fFormat == SkMask::kLCD16_Format) {
+        return; // needs to be handled by subclass
+    }
+
     if (mask.fFormat == SkMask::kBW_Format) {
         int cx = clip.fLeft;
         int cy = clip.fTop;
         int maskLeft = mask.fBounds.fLeft;
         int maskRowBytes = mask.fRowBytes;
         int height = clip.height();
 
         const uint8_t* bits = mask.getAddr1(cx, cy);
 
         SkDEBUGCODE(const uint8_t* endOfImage =
@@ skipping 851 matching lines @@
     fShaderContext->~Context();
     SkShader::Context* ctx = fShader->createContext(rec, (void*)fShaderContext);
     if (nullptr == ctx) {
         // Need a valid context in fShaderContext's storage, so we can later (or our caller) call
         // the in-place destructor.
         new (fShaderContext) SkZeroShaderContext(*fShader, rec);
         return false;
     }
     return true;
 }