C++17: use android::base::Trim instead of std::not1/std::ptr_fun.

These were deprecated in C++14 and removed in C++17. (Sadly we don't
give deprecation warnings.)

This code is already using libbase, so just switch over.

Bug: http://b/111067277
Test: builds
Change-Id: I5f884aa4d8d6b5d559e14323b1a647cc45cdad9f
diff --git a/services/vr/performanced/task.cpp b/services/vr/performanced/task.cpp
index bda1682..2fc96bf 100644
--- a/services/vr/performanced/task.cpp
+++ b/services/vr/performanced/task.cpp
@@ -10,10 +10,10 @@
 #include <memory>
 #include <sstream>
 
+#include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 
 #include "stdio_filebuf.h"
-#include "string_trim.h"
 
 namespace {
 
@@ -102,7 +102,7 @@
 
       // The status file has lines with the format <field>:<value>. Extract the
       // value after the colon.
-      return Trim(line.substr(offset + field.size() + 1));
+      return android::base::Trim(line.substr(offset + field.size() + 1));
     }
   }
 
@@ -123,7 +123,7 @@
       }
 
       std::string key = line.substr(0, offset);
-      std::string value = Trim(line.substr(offset + 1));
+      std::string value = android::base::Trim(line.substr(offset + 1));
 
       ALOGD_IF(TRACE, "Task::ReadStatusFields: key=\"%s\" value=\"%s\"",
                key.c_str(), value.c_str());
@@ -156,7 +156,7 @@
     std::string line = "";
     std::getline(file_stream, line);
 
-    return Trim(line);
+    return android::base::Trim(line);
   } else {
     return "";
   }