Working plumb of image scaling:

src/core/SkBitmapFilter.cpp

Index: src/core/SkBitmapFilter.cpp
diff --git a/src/core/SkBitmapFilter.cpp b/src/core/SkBitmapFilter.cpp
index 3cbafd743c1eb9943b451f0a8129105b32da3253..2b9520d270ac3f9ea2965bc6c24e2960de64b645 100644
--- a/src/core/SkBitmapFilter.cpp
+++ b/src/core/SkBitmapFilter.cpp
@@ -147,12 +147,13 @@ static SkBitmapFilter *allocateBitmapFilter() {
 }
 
 SkBitmapProcState::ShaderProc32
-SkBitmapProcState::chooseBitmapFilterProc(const SkPaint& paint) {
-    // we need to be requested
-    uint32_t mask = SkPaint::kFilterBitmap_Flag
-                  | SkPaint::kHighQualityFilterBitmap_Flag
-                  ;
-    if ((paint.getFlags() & mask) != mask) {
+SkBitmapProcState::chooseBitmapFilterProc() {
+
+    if (fFilterQuality != kHQ_BitmapFilter) {
+        return NULL;
+    }
+    
+    if (fAlphaScale != 256) {
         return NULL;
     }
 
@@ -166,11 +167,6 @@ SkBitmapProcState::chooseBitmapFilterProc(const SkPaint& paint) {
         return NULL;
     }
 
-    // TODO: support blending inside our procs
-    if (0xFF != paint.getAlpha()) {
-        return NULL;
-    }
-
     if (fInvType & (SkMatrix::kAffine_Mask | SkMatrix::kScale_Mask)) {
         fBitmapFilter = allocateBitmapFilter();
     }