Implements a new class, SkSingleInputImageFilter, to handle DAG connectivity
for filters with a single image input.  This provides functionality to store,
flatten and unflatten a single SkImageFilter input, as well as to recursively
evaluate it on the CPU or GPU.  The following classes were re-parented to 
implement DAG connectivity:  SkBlurImageFilter, SkDilateImageFilter,
SkErodeImageFilter, SkColorFilterImageFilter.  The constructors for each
have been appended with a new parameter, representing the input filter
(default NULL).

This change also implements an arbitrary SkBitmap input source for filtering,
SkBitmapSource.

NOTE:  This CL will require gyp file changes when rolling past this revision.

Review URL:  https://codereview.appspot.com/6462071/



git-svn-id: http://skia.googlecode.com/svn/trunk@5170 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/effects/SkBitmapSource.h b/include/effects/SkBitmapSource.h
new file mode 100644
index 0000000..5e07e9e
--- /dev/null
+++ b/include/effects/SkBitmapSource.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2012 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.
+ */
+
+
+#ifndef SkBitmapSource_DEFINED
+#define SkBitmapSource_DEFINED
+
+#include "SkImageFilter.h"
+#include "SkBitmap.h"
+
+class SK_API SkBitmapSource : public SkImageFilter {
+public:
+    explicit SkBitmapSource(const SkBitmap& bitmap);
+
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBitmapSource)
+
+protected:
+    explicit SkBitmapSource(SkFlattenableReadBuffer& buffer);
+    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
+    virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
+                               SkBitmap* result, SkIPoint* offset) SK_OVERRIDE;
+
+private:
+    SkBitmap fBitmap;
+    typedef SkImageFilter INHERITED;
+};
+
+#endif
+