Fix some usage of removed private Skia functions & transitive dep

Attempting to fix broken roll.

sk_float_* functions map directly to <cmath> functions now, see
https://skia-review.googlesource.com/c/skia/+/842498

SkiaInterpolator requires <cstring> for memcpy. It seems this was
previously being pulled in through a transitive Skia inclusion which
is no longer present.

Bug: none
Change-Id: I155ead6c68eab066fb4d5588f35523aff2c4a050
Test: builds
Flag: EXEMPT build fix
diff --git a/libs/hwui/effects/GainmapRenderer.cpp b/libs/hwui/effects/GainmapRenderer.cpp
index 3ebf7d1..0a30c6c 100644
--- a/libs/hwui/effects/GainmapRenderer.cpp
+++ b/libs/hwui/effects/GainmapRenderer.cpp
@@ -32,6 +32,8 @@
 #include "src/core/SkColorFilterPriv.h"
 #include "src/core/SkImageInfoPriv.h"
 #include "src/core/SkRuntimeEffectPriv.h"
+
+#include <cmath>
 #endif
 
 namespace android::uirenderer {
@@ -206,12 +208,12 @@
 
     void setupGenericUniforms(const sk_sp<const SkImage>& gainmapImage,
                               const SkGainmapInfo& gainmapInfo) {
-        const SkColor4f logRatioMin({sk_float_log(gainmapInfo.fGainmapRatioMin.fR),
-                                     sk_float_log(gainmapInfo.fGainmapRatioMin.fG),
-                                     sk_float_log(gainmapInfo.fGainmapRatioMin.fB), 1.f});
-        const SkColor4f logRatioMax({sk_float_log(gainmapInfo.fGainmapRatioMax.fR),
-                                     sk_float_log(gainmapInfo.fGainmapRatioMax.fG),
-                                     sk_float_log(gainmapInfo.fGainmapRatioMax.fB), 1.f});
+        const SkColor4f logRatioMin({std::log(gainmapInfo.fGainmapRatioMin.fR),
+                                     std::log(gainmapInfo.fGainmapRatioMin.fG),
+                                     std::log(gainmapInfo.fGainmapRatioMin.fB), 1.f});
+        const SkColor4f logRatioMax({std::log(gainmapInfo.fGainmapRatioMax.fR),
+                                     std::log(gainmapInfo.fGainmapRatioMax.fG),
+                                     std::log(gainmapInfo.fGainmapRatioMax.fB), 1.f});
         const int noGamma = gainmapInfo.fGainmapGamma.fR == 1.f &&
                             gainmapInfo.fGainmapGamma.fG == 1.f &&
                             gainmapInfo.fGainmapGamma.fB == 1.f;
@@ -248,10 +250,10 @@
             float W = 0.f;
             if (targetHdrSdrRatio > mGainmapInfo.fDisplayRatioSdr) {
                 if (targetHdrSdrRatio < mGainmapInfo.fDisplayRatioHdr) {
-                    W = (sk_float_log(targetHdrSdrRatio) -
-                         sk_float_log(mGainmapInfo.fDisplayRatioSdr)) /
-                        (sk_float_log(mGainmapInfo.fDisplayRatioHdr) -
-                         sk_float_log(mGainmapInfo.fDisplayRatioSdr));
+                    W = (std::log(targetHdrSdrRatio) -
+                         std::log(mGainmapInfo.fDisplayRatioSdr)) /
+                        (std::log(mGainmapInfo.fDisplayRatioHdr) -
+                         std::log(mGainmapInfo.fDisplayRatioSdr));
                 } else {
                     W = 1.f;
                 }