linux: fix race in TransportDIB passing

chrome/common/transport_dib_linux.cc

Index: chrome/common/transport_dib_linux.cc
diff --git a/chrome/common/transport_dib_linux.cc b/chrome/common/transport_dib_linux.cc
index d239da2a8cca67b4f7f837245fb8597dfb1d3b80..d3ffe6937a58d9668fa896c80df6bab814c1ecdc 100644
--- a/chrome/common/transport_dib_linux.cc
+++ b/chrome/common/transport_dib_linux.cc
@@ -45,7 +45,7 @@ TransportDIB* TransportDIB::Create(size_t size, uint32 sequence_num) {
   if (shmkey == -1) {
     DLOG(ERROR) << "Failed to create SysV shared memory region"
                 << " errno:" << errno;
-    return false;
+    return NULL;
   }
 
   void* address = shmat(shmkey, NULL /* desired address */, 0 /* flags */);
@@ -54,7 +54,7 @@ TransportDIB* TransportDIB::Create(size_t size, uint32 sequence_num) {
   // that the kernel will automatically clean it up for us.
   shmctl(shmkey, IPC_RMID, 0);
   if (address == kInvalidAddress)
-    return false;
+    return NULL;
 
   TransportDIB* dib = new TransportDIB;