Revert 148351 - Make dbus file descriptor check dynamic

Without this change cros builds from outside the chroot can't run
tracing code.

BUG=None
TEST=None

Review URL: https://chromiumcodereview.appspot.com/10815083

TBR=davemoore@chromium.org
Review URL: https://chromiumcodereview.appspot.com/10822016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148353 0039d316-1c4b-4281-b951-d872f2087c98

dbus/message.cc

@@ -18,7 +18,7 @@ namespace {
 
 // Appends the header name and the value to |output|, if the value is
 // not empty.
-void AppendStringHeader(const std::string& header_name,
+static void AppendStringHeader(const std::string& header_name,
                                const std::string& header_value,
                                std::string* output) {
   if (!header_value.empty()) {
@@ -28,7 +28,7 @@ void AppendStringHeader(const std::string& header_name,
 
 // Appends the header name and the value to |output|, if the value is
 // nonzero.
-void AppendUint32Header(const std::string& header_name,
+static void AppendUint32Header(const std::string& header_name,
                                uint32 header_value,
                                std::string* output) {
   if (header_value != 0) {
@@ -37,15 +37,6 @@ void AppendUint32Header(const std::string& header_name,
   }
 }
 
-// Returns true if Unix FD passing is supported in libdbus.
-// The check is done runtime rather than compile time as the libdbus
-// version used at runtime may be different from the one used at compile time.
-bool IsDBusTypeUnixFdSupported() {
-  int major = 0, minor = 0, micro = 0;
-  dbus_get_version(&major, &minor, &micro);
-  return major >= 1 && minor >= 4;
-}
-
 }  // namespace
 
 namespace dbus {
@@ -220,7 +211,7 @@ std::string Message::ToStringInternal(const std::string& indent,
         break;
       }
       case UNIX_FD: {
-        CHECK(IsDBusTypeUnixFdSupported());
+        CHECK(kDBusTypeUnixFdIsSupported);
 
         FileDescriptor file_descriptor;
         if (!reader->PopFileDescriptor(&file_descriptor))
@@ -699,7 +690,7 @@ void MessageWriter::AppendVariantOfBasic(int dbus_type, const void* value) {
 }
 
 void MessageWriter::AppendFileDescriptor(const FileDescriptor& value) {
-  CHECK(IsDBusTypeUnixFdSupported());
+  CHECK(kDBusTypeUnixFdIsSupported);
 
   if (!value.is_valid()) {
     // NB: sending a directory potentially enables sandbox escape
@@ -969,7 +960,7 @@ bool MessageReader::PopVariantOfBasic(int dbus_type, void* value) {
 }
 
 bool MessageReader::PopFileDescriptor(FileDescriptor* value) {
-  CHECK(IsDBusTypeUnixFdSupported());
+  CHECK(kDBusTypeUnixFdIsSupported);
 
   int fd = -1;
   const bool success = PopBasic(DBUS_TYPE_UNIX_FD, &fd);

dbus/message.h

@@ -28,7 +28,10 @@ class MessageWriter;
 class MessageReader;
 
 // DBUS_TYPE_UNIX_FD was added in D-Bus version 1.4
-#if !defined(DBUS_TYPE_UNIX_FD)
+#if defined(DBUS_TYPE_UNIX_FD)
+const bool kDBusTypeUnixFdIsSupported = true;
+#else
+const bool kDBusTypeUnixFdIsSupported = false;
 #define DBUS_TYPE_UNIX_FD      ((int) 'h')
 #endif