Guard against most unintentionally ephemeral SkAutoFoo instantiations.

include/core/SkBitmap.h

Index: include/core/SkBitmap.h
diff --git a/include/core/SkBitmap.h b/include/core/SkBitmap.h
index dd2d2cfd7f10a255c2ba463af54191ad450e2492..d9749f04c4393e36170906e0981fbccb134d00b2 100644
--- a/include/core/SkBitmap.h
+++ b/include/core/SkBitmap.h
@@ -730,6 +730,7 @@ private:
     const SkBitmap& fBitmap;
     bool            fDidLock;
 };
+#define SkAutoLockPixels(...) SK_REQUIRE_LOCAL_VAR(SkAutoLockPixels)
 
 /** Helper class that performs the lock/unlockColors calls on a colortable.
     The destructor will call unlockColors(false) if it has a bitmap's colortable
@@ -783,6 +784,7 @@ private:
     SkColorTable*    fCTable;
     const SkPMColor* fColors;
 };
+#define SkAutoLockColors(...) SK_REQUIRE_LOCAL_VAR(SkAutoLockColors)
 
 ///////////////////////////////////////////////////////////////////////////////