Avoid overflow in WebRtcSpl_DotProductWithScale

webrtc/common_audio/signal_processing/include/signal_processing_library.h

Index: webrtc/common_audio/signal_processing/include/signal_processing_library.h
diff --git a/webrtc/common_audio/signal_processing/include/signal_processing_library.h b/webrtc/common_audio/signal_processing/include/signal_processing_library.h
index 7fa68e04226e3c13be8eb9b73f8dc112758be93f..c8d4bce5de9aaf96d4b18db15d10cbe76b905f32 100644
--- a/webrtc/common_audio/signal_processing/include/signal_processing_library.h
+++ b/webrtc/common_audio/signal_processing/include/signal_processing_library.h
@@ -19,6 +19,7 @@
 #define WEBRTC_SPL_SIGNAL_PROCESSING_LIBRARY_H_
 
 #include <string.h>
+#include "webrtc/common_audio/signal_processing/dot_product_with_scale.h"
 #include "webrtc/typedefs.h"
 
 // Macros specific for the fixed point implementation
@@ -608,10 +609,10 @@ int32_t WebRtcSpl_Energy(int16_t* vector,
 //                        output will be in Q(-|scaling|)
 //
 // Return value         : The dot product in Q(-scaling)
-int32_t WebRtcSpl_DotProductWithScale(const int16_t* vector1,
-                                      const int16_t* vector2,
-                                      size_t length,
-                                      int scaling);
+// int32_t WebRtcSpl_DotProductWithScale(const int16_t* vector1,

[hlundin-webrtc, 2017/02/28 12:35:17]

The declaration is intentionally left in this file. I think this is the pattern
used here, so that this file serves as the master catalog for SPL functions.

[kwiberg-webrtc, 2017/02/28 12:51:01]

I think this is a bad idea. It's just a question of time before this comment and
the real declaration diverge.

This is a job for doxygen or something similar.

[hlundin-webrtc, 2017/03/06 12:43:26]

Would you like me to keep lines 601--611 in this file?

[kwiberg-webrtc, 2017/03/06 14:35:50]

I would prefer that you delete WebRtcSpl_DotProductWithScale entirely from this
file and have it just in the new header. Having it just in this file is still
better than duplicating the information, though. Duplication is a public health
hazard...

Oh, but wait. If you keep it here, you'll need to make this header part of both
build targets. (You can't put it in just one and have a dep for the other,
because you'll end up with circular deps.) If that's OK, you can keep the
declaration here. Otherwise, my recommendation is the usual 1:1 relationship
between .h and .cc files...

[hlundin-webrtc, 2017/03/06 15:44:23]

Done.

+//                                       const int16_t* vector2,
+//                                       size_t length,
+//                                       int scaling);
 
 // Filter operations.
 size_t WebRtcSpl_FilterAR(const int16_t* ar_coef,