installPixels returns true if null-pixels -- devolving to setConfig

src/core/SkBitmap.cpp

Index: src/core/SkBitmap.cpp
diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index b6c2e2f65ccd4dc8e4cd50e883c6586df94f0d1a..5b83b44a66375ff391090c4689c8f94400d6387c 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -503,6 +503,11 @@ bool SkBitmap::installPixels(const SkImageInfo& info, void* pixels, size_t rb,
         return false;
     }
 
+    // No pixels means just behave like setConfig()
+    if (NULL == pixels) {
+        return true;
+    }
+
     SkPixelRef* pr = SkMallocPixelRef::NewWithProc(info, rb, NULL, pixels,
                                                    releaseProc, context);
     if (!pr) {