Avoid overflow in WebRtcSpl_DotProductWithScale

webrtc/common_audio/signal_processing/dot_product_with_scale.cc

Index: webrtc/common_audio/signal_processing/dot_product_with_scale.cc
diff --git a/webrtc/common_audio/signal_processing/dot_product_with_scale.c b/webrtc/common_audio/signal_processing/dot_product_with_scale.cc
similarity index 91%
rename from webrtc/common_audio/signal_processing/dot_product_with_scale.c
rename to webrtc/common_audio/signal_processing/dot_product_with_scale.cc
index 1302d62541266fdc45b07576de5ff5026d69032f..f8b2288b53007235a32e4479a1f651a1c6c9e56a 100644
--- a/webrtc/common_audio/signal_processing/dot_product_with_scale.c
+++ b/webrtc/common_audio/signal_processing/dot_product_with_scale.cc
@@ -10,11 +10,13 @@
 
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 
+#include "webrtc/base/safe_conversions.h"
+
 int32_t WebRtcSpl_DotProductWithScale(const int16_t* vector1,
                                       const int16_t* vector2,
                                       size_t length,
                                       int scaling) {
-  int32_t sum = 0;
+  int64_t sum = 0;
   size_t i = 0;
 
   /* Unroll the loop to improve performance. */
@@ -28,5 +30,5 @@ int32_t WebRtcSpl_DotProductWithScale(const int16_t* vector1,
     sum += (vector1[i] * vector2[i]) >> scaling;
   }
 
-  return sum;
+  return rtc::saturated_cast<int32_t>(sum);
 }