Add vector_math::FMUL. Replace audio_util::AdjustVolume.

media/base/simd/vector_math_sse.cc

Index: media/base/simd/vector_math_sse.cc
diff --git a/media/base/simd/vector_math_sse.cc b/media/base/simd/vector_math_sse.cc
index 5cc2df96325ad16701961abd52a3a0faf2bcd0d4..39bcaa0c195fd0dd2570b37065f0df7fdd3a9b7d 100644
--- a/media/base/simd/vector_math_sse.cc
+++ b/media/base/simd/vector_math_sse.cc
@@ -9,6 +9,18 @@
 namespace media {
 namespace vector_math {
 
+void FMUL_SSE(const float src[], float scale, int len, float dest[]) {
+  const int rem = len % 4;
+  const int last_index = len - rem;
+  __m128 m_scale = _mm_set_ps1(scale);
+  for (int i = 0; i < last_index; i += 4)
+    _mm_store_ps(dest + i, _mm_mul_ps(_mm_load_ps(src + i), m_scale));
+
+  // Handle any remaining values that wouldn't fit in an SSE pass.
+  for (int i = last_index; i < len; ++i)
+    dest[i] = src[i] * scale;
+}
+
 void FMAC_SSE(const float src[], float scale, int len, float dest[]) {
   const int rem = len % 4;
   const int last_index = len - rem;