GpuArcVideoService

components/arc/arc_bridge_bootstrap.cc

Index: components/arc/arc_bridge_bootstrap.cc
diff --git a/components/arc/arc_bridge_bootstrap.cc b/components/arc/arc_bridge_bootstrap.cc
index 1d7a94f55178b590325f95b1ce23fff6f1c2afb5..6fcee5507d3a6be719fc56fbe268282f786e49c0 100644
--- a/components/arc/arc_bridge_bootstrap.cc
+++ b/components/arc/arc_bridge_bootstrap.cc
@@ -32,17 +32,15 @@
 
 namespace arc {
 
-namespace {
+// This assumes all video accelerator clients are from the same namespace and
+// the max pid of the said namespace is kPidMask.
+base::ProcessHandle RemapChildPid(base::ProcessHandle pid) {
+  uint32_t kPidBase = 0x3DE0EA7C;  // arbitrarily chosen.
+  uint32_t kPidMask = 0x7fff;      // the default, 32k.
+  return kPidBase + (pid & kPidMask);
+}
 
-// We do not know the PID of ARC, since Chrome does not create it directly.
-// Since Mojo in POSIX does not use the child PID except as an unique
-// identifier for the routing table, rather than doing a lot of plumbing in the
-// whole system to get the correct PID, just use an arbitrary number that will
-// never be used by a legitimate process. Chrome OS assigns unassigned PIDs
-// sequentially until it reaches a certain maximum value (Chrome OS uses the
-// default value of 32k), at which point it loops around to zero. An arbitrary
-// number larger than the maximum should be safe.
-const pid_t kArcPid = 0x3DE0EA7C;
+namespace {
 
 const base::FilePath::CharType kArcBridgeSocketPath[] =
     FILE_PATH_LITERAL("/var/run/chrome/arc_bridge.sock");
@@ -260,6 +258,11 @@ base::ScopedFD ArcBridgeBootstrapImpl::AcceptInstanceConnection(
   }
   base::ScopedFD scoped_fd(raw_fd);
 
+  // We do not know the PID of ARC, since Chrome does not create it directly
+  // and it may in the difference namespace. Here we assume the pid is zero
+  // (should not happen in its namespace) and RemapChildPid to safe range (not
+  // conflict in our namespace).
+  const base::ProcessHandle kArcPid = RemapChildPid(0);
   mojo::edk::ScopedPlatformHandle child_handle =
       mojo::edk::ChildProcessLaunched(kArcPid);