Bump to WebRTC M120 release

Some API deprecation -- ExperimentalAgc and ExperimentalNs are gone.
We're continuing to carry iSAC even though it's gone upstream, but maybe
we'll want to drop that soon.

webrtc/rtc_base/string_encode.h

@@ -17,7 +17,9 @@
 #include <type_traits>
 #include <vector>
 
+#include "absl/strings/string_view.h"
 #include "absl/types/optional.h"
+#include "api/array_view.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/string_to_number.h"
 
@@ -27,79 +29,36 @@ namespace rtc {
 // String Encoding Utilities
 //////////////////////////////////////////////////////////////////////
 
-std::string hex_encode(const std::string& str);
-std::string hex_encode(const char* source, size_t srclen);
-std::string hex_encode_with_delimiter(const char* source,
-                                      size_t srclen,
-                                      char delimiter);
+std::string hex_encode(absl::string_view str);
+std::string hex_encode_with_delimiter(absl::string_view source, char delimiter);
 
 // hex_decode converts ascii hex to binary.
-size_t hex_decode(char* buffer,
-                  size_t buflen,
-                  const char* source,
-                  size_t srclen);
+size_t hex_decode(ArrayView<char> buffer, absl::string_view source);
 
 // hex_decode, assuming that there is a delimiter between every byte
 // pair.
-// |delimiter| == 0 means no delimiter
+// `delimiter` == 0 means no delimiter
 // If the buffer is too short or the data is invalid, we return 0.
-size_t hex_decode_with_delimiter(char* buffer,
-                                 size_t buflen,
-                                 const char* source,
-                                 size_t srclen,
+size_t hex_decode_with_delimiter(ArrayView<char> buffer,
+                                 absl::string_view source,
                                  char delimiter);
 
-// Helper functions for hex_decode.
-size_t hex_decode(char* buffer, size_t buflen, const std::string& source);
-size_t hex_decode_with_delimiter(char* buffer,
-                                 size_t buflen,
-                                 const std::string& source,
-                                 char delimiter);
-
-// Joins the source vector of strings into a single string, with each
-// field in source being separated by delimiter. No trailing delimiter is added.
-std::string join(const std::vector<std::string>& source, char delimiter);
-
 // Splits the source string into multiple fields separated by delimiter,
-// with duplicates of delimiter creating empty fields.
-size_t split(const std::string& source,
-             char delimiter,
-             std::vector<std::string>* fields);
+// with duplicates of delimiter creating empty fields. Empty input produces a
+// single, empty, field.
+std::vector<absl::string_view> split(absl::string_view source, char delimiter);
 
 // Splits the source string into multiple fields separated by delimiter,
 // with duplicates of delimiter ignored.  Trailing delimiter ignored.
-size_t tokenize(const std::string& source,
+size_t tokenize(absl::string_view source,
                 char delimiter,
                 std::vector<std::string>* fields);
 
-// Tokenize, including the empty tokens.
-size_t tokenize_with_empty_tokens(const std::string& source,
-                                  char delimiter,
-                                  std::vector<std::string>* fields);
-
-// Tokenize and append the tokens to fields. Return the new size of fields.
-size_t tokenize_append(const std::string& source,
-                       char delimiter,
-                       std::vector<std::string>* fields);
-
-// Splits the source string into multiple fields separated by delimiter, with
-// duplicates of delimiter ignored. Trailing delimiter ignored. A substring in
-// between the start_mark and the end_mark is treated as a single field. Return
-// the size of fields. For example, if source is "filename
-// \"/Library/Application Support/media content.txt\"", delimiter is ' ', and
-// the start_mark and end_mark are '"', this method returns two fields:
-// "filename" and "/Library/Application Support/media content.txt".
-size_t tokenize(const std::string& source,
-                char delimiter,
-                char start_mark,
-                char end_mark,
-                std::vector<std::string>* fields);
-
 // Extract the first token from source as separated by delimiter, with
 // duplicates of delimiter ignored. Return false if the delimiter could not be
 // found, otherwise return true.
-bool tokenize_first(const std::string& source,
-                    const char delimiter,
+bool tokenize_first(absl::string_view source,
+                    char delimiter,
                     std::string* token,
                     std::string* rest);
 
@@ -107,8 +66,10 @@ bool tokenize_first(const std::string& source,
 // TODO(jonasolsson): Remove these when absl::StrCat becomes available.
 std::string ToString(bool b);
 
+std::string ToString(absl::string_view s);
+// The const char* overload is needed for correct overload resolution because of
+// the const void* version of ToString() below.
 std::string ToString(const char* s);
-std::string ToString(std::string t);
 
 std::string ToString(short s);
 std::string ToString(unsigned short s);
@@ -128,7 +89,7 @@ template <typename T,
           typename std::enable_if<std::is_arithmetic<T>::value &&
                                       !std::is_same<T, bool>::value,
                                   int>::type = 0>
-static bool FromString(const std::string& s, T* t) {
+static bool FromString(absl::string_view s, T* t) {
   RTC_DCHECK(t);
   absl::optional<T> result = StringToNumber<T>(s);
 
@@ -138,10 +99,10 @@ static bool FromString(const std::string& s, T* t) {
   return result.has_value();
 }
 
-bool FromString(const std::string& s, bool* b);
+bool FromString(absl::string_view s, bool* b);
 
 template <typename T>
-static inline T FromString(const std::string& str) {
+static inline T FromString(absl::string_view str) {
   T val;
   FromString(str, &val);
   return val;