misc fixes to make float buffers work a little better

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1703013002

TBR=fmalita

Review URL: https://codereview.chromium.org/1703013002
diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index bdf1daa..fdb66b3 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -563,6 +563,8 @@
     return base;
 }
 
+#include "SkHalf.h"
+
 SkColor SkBitmap::getColor(int x, int y) const {
     SkASSERT((unsigned)x < (unsigned)this->width());
     SkASSERT((unsigned)y < (unsigned)this->height());
@@ -599,6 +601,18 @@
             SkPMColor c = SkSwizzle_RGBA_to_PMColor(addr[0]);
             return SkUnPreMultiply::PMColorToColor(c);
         }
+        case kRGBA_F16_SkColorType: {
+            const uint64_t* addr = (const uint64_t*)fPixels + y * (fRowBytes >> 3) + x;
+            Sk4f p4 = SkHalfToFloat_01(addr[0]);
+            if (p4[3]) {
+                float inva = 1 / p4[3];
+                p4 = p4 * Sk4f(inva, inva, inva, 1);
+            }
+            SkColor c;
+            SkNx_cast<uint8_t>(p4 * Sk4f(255) + Sk4f(0.5f)).store(&c);
+            // p4 is RGBA, but we want BGRA, so we need to swap next
+            return SkSwizzle_RB(c);
+        }
         default:
             SkASSERT(false);
             return 0;
diff --git a/src/core/SkBlitter.cpp b/src/core/SkBlitter.cpp
index 45219c5..a3dbe5e 100644
--- a/src/core/SkBlitter.cpp
+++ b/src/core/SkBlitter.cpp
@@ -127,6 +127,10 @@
 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;
diff --git a/src/core/SkConfig8888.cpp b/src/core/SkConfig8888.cpp
index 53f35c3..e2dd102 100644
--- a/src/core/SkConfig8888.cpp
+++ b/src/core/SkConfig8888.cpp
@@ -173,9 +173,20 @@
     if (srcInfo.dimensions() != dstInfo.dimensions()) {
         return false;
     }
-
+    
     const int width = srcInfo.width();
     const int height = srcInfo.height();
+    
+    // Do the easiest one first : both configs are equal
+    if ((srcInfo == dstInfo) && !ctable) {
+        size_t bytes = width * srcInfo.bytesPerPixel();
+        for (int y = 0; y < height; ++y) {
+            memcpy(dstPixels, srcPixels, bytes);
+            srcPixels = (const char*)srcPixels + srcRB;
+            dstPixels = (char*)dstPixels + dstRB;
+        }
+        return true;
+    }
 
     // Handle fancy alpha swizzling if both are ARGB32
     if (4 == srcInfo.bytesPerPixel() && 4 == dstInfo.bytesPerPixel()) {