[sql] Enable HAVE_USLEEP for more platforms.

third_party/sqlite/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 config("sqlite_config") {
   include_dirs = [ "." ]
 }
 
 source_set("sqlite") {
   sources = [
@@ skipping 27 matching lines @@
     "_HAS_EXCEPTIONS=0",
   ]
   if (is_chromeos) {
     defines += [
       # Despite obvious warnings about not using this flag in deployment, we
       # are turning off sync in ChromeOS and relying on the underlying
       # journaling filesystem to do error recovery properly. It's much faster.
       "SQLITE_NO_SYNC",
     ]
   }
+  if (is_posix) {
+    defines += [
+      # Allow xSleep() call on Unix to use usleep() rather than sleep(), so it
+      # will have microsecond precision.  Should only affect contended databases
+      # via the busy callback.  Browser profile databases are mostly exclusive,
+      # but renderer databases may allow for contention.
+      "HAVE_USLEEP=1",
+    ]
+  }
 
   include_dirs = [
     "amalgamation",
     "src/src",  # Needed for fts2 to build.
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 
   if (is_win) {
     cflags += [ "/wd4267" ]  # Conversion from size_t to "type".
   } else if (is_linux) {
     cflags += [
       # SQLite doesn"t believe in compiler warnings,
       # preferring testing.
       #   http://www.sqlite.org/faq.html#q17
       "-Wno-int-to-pointer-cast",
       "-Wno-pointer-to-int-cast",
     ]
     libs = [ "dl" ]
   } else if (is_mac || is_ios) {
     libs = [ "CoreFoundation.framework" ]
   } else if (is_android) {
     defines += [
-      "HAVE_USLEEP=1",
       "SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT=1048576",
       "SQLITE_DEFAULT_AUTOVACUUM=1",
       "SQLITE_TEMP_STORE=3",
       "SQLITE_ENABLE_FTS3_BACKWARDS",
       "DSQLITE_DEFAULT_FILE_FORMAT=4",
     ]
   }
 
   if (is_clang) {
     cflags += [
@@ skipping 36 matching lines @@
 if (is_ios) {
   source_set("sqlite_regexp") {
     sources = [
       "src/ext/icu/icu.c",
     ]
     deps = [
       "//third_party/icu",
     ]
   }
 }