disable LCD for layers w/ filters

src/core/SkDevice.cpp

Index: src/core/SkDevice.cpp
diff --git a/src/core/SkDevice.cpp b/src/core/SkDevice.cpp
index d76a1808628418246f183b51e6bd59b2acf4948e..6be9178f2386d785e5467f0b46d0aa86c343cf8a 100644
--- a/src/core/SkDevice.cpp
+++ b/src/core/SkDevice.cpp
@@ -68,6 +68,9 @@ SkPixelGeometry SkBaseDevice::CreateInfo::AdjustGeometry(const SkImageInfo& info
                                                          SkPixelGeometry geo) {
     switch (tileUsage) {
         case kPossible_TileUsage:
+            // (we think) for compatibility with old clients, we assume this layer can support LCD
+            // even though they may not have marked it as opaque... seems like we should update
+            // our callers (reed/robertphilips).
             break;
         case kNever_TileUsage:
             if (info.alphaType() != kOpaque_SkAlphaType) {