Move SkComposeImageFilter into its own {.h, .cpp} files

src/effects/SkComposeImageFilter.cpp

Index: src/effects/SkComposeImageFilter.cpp
diff --git a/src/effects/SkComposeImageFilter.cpp b/src/effects/SkComposeImageFilter.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..2ba2f3df276d1004c269a5584e69ca7098e20aa7
--- /dev/null
+++ b/src/effects/SkComposeImageFilter.cpp
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkBitmap.h"
+#include "SkComposeImageFilter.h"
+#include "SkFlattenableBuffers.h"
+
+SkComposeImageFilter::~SkComposeImageFilter() {
+}
+
+bool SkComposeImageFilter::onFilterImage(Proxy* proxy,
+                                         const SkBitmap& src,
+                                         const SkMatrix& ctm,
+                                         SkBitmap* result,
+                                         SkIPoint* loc) {
+    SkImageFilter* outer = getInput(0);
+    SkImageFilter* inner = getInput(1);
+
+    if (!outer && !inner) {
+        return false;
+    }
+
+    if (!outer || !inner) {
+        return (outer ? outer : inner)->filterImage(proxy, src, ctm, result, loc);
+    }
+
+    SkBitmap tmp;
+    return inner->filterImage(proxy, src, ctm, &tmp, loc) &&
+           outer->filterImage(proxy, tmp, ctm, result, loc);
+}
+
+bool SkComposeImageFilter::onFilterBounds(const SkIRect& src,
+                                          const SkMatrix& ctm,
+                                          SkIRect* dst) {
+    SkImageFilter* outer = getInput(0);
+    SkImageFilter* inner = getInput(1);
+
+    if (!outer && !inner) {
+        return false;
+    }
+
+    if (!outer || !inner) {
+        return (outer ? outer : inner)->filterBounds(src, ctm, dst);
+    }
+
+    SkIRect tmp;
+    return inner->filterBounds(src, ctm, &tmp) &&
+           outer->filterBounds(tmp, ctm, dst);
+}
+
+SkComposeImageFilter::SkComposeImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
+}