change gpudevice and pdfdevice to inherit from basedevice

src/core/SkBitmapDevice.cpp

Index: src/core/SkBitmapDevice.cpp
diff --git a/src/core/SkBitmapDevice.cpp b/src/core/SkBitmapDevice.cpp
index 0f3cc2be501450d8e9271f06f046d62f204ddde8..86c5702f03845400a38fac4c6dd977fcbc8b136b 100644
--- a/src/core/SkBitmapDevice.cpp
+++ b/src/core/SkBitmapDevice.cpp
@@ -132,20 +132,6 @@ const SkBitmap& SkBitmapDevice::onAccessBitmap() {
     return fBitmap;
 }
 
-bool SkBitmapDevice::canHandleImageFilter(const SkImageFilter*) {
-    return false;
-}
-
-bool SkBitmapDevice::filterImage(const SkImageFilter* filter, const SkBitmap& src,
-                                 const SkImageFilter::Context& ctx, SkBitmap* result,
-                                 SkIPoint* offset) {
-    return false;
-}
-
-bool SkBitmapDevice::allowImageFilter(const SkImageFilter*) {
-    return true;
-}
-
 void* SkBitmapDevice::onAccessPixels(SkImageInfo* info, size_t* rowBytes) {
     if (fBitmap.getPixels()) {
         *info = fBitmap.info();