Back out r269483 and the line of fixes that followed it.

content/browser/mach_broker_mac.mm

Index: content/browser/mach_broker_mac.mm
diff --git a/content/browser/mach_broker_mac.mm b/content/browser/mach_broker_mac.mm
index 1e790c9768e8644ae3c6c04ad9e08113ad624f84..24a0e2498134e941fab023ab22c307b156454beb 100644
--- a/content/browser/mach_broker_mac.mm
+++ b/content/browser/mach_broker_mac.mm
@@ -12,7 +12,6 @@
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
-#include "base/mac/mach_logging.h"
 #include "base/mac/scoped_mach_port.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ -29,6 +28,11 @@ namespace content {
 
 namespace {
 
+// Prints a string representation of a Mach error code.
+std::string MachErrorCode(kern_return_t err) {
+  return base::StringPrintf("0x%x %s", err, mach_error_string(err));
+}
+
 // Mach message structure used in the child as a sending message.
 struct MachBroker_ChildSendMsg {
   mach_msg_header_t header;
@@ -60,7 +64,8 @@ class MachListenerThreadDelegate : public base::PlatformThread::Delegate {
                                           MACH_PORT_RIGHT_RECEIVE,
                                           &port);
     if (kr != KERN_SUCCESS) {
-      MACH_LOG(ERROR, kr) << "mach_port_allocate";
+      LOG(ERROR) << "Failed to allocate MachBroker server port: "
+                 << MachErrorCode(kr);
       return false;
     }
 
@@ -68,7 +73,8 @@ class MachListenerThreadDelegate : public base::PlatformThread::Delegate {
     kr = mach_port_insert_right(
         mach_task_self(), port, port, MACH_MSG_TYPE_MAKE_SEND);
     if (kr != KERN_SUCCESS) {
-      MACH_LOG(ERROR, kr) << "mach_port_insert_right";
+      LOG(ERROR) << "Failed to insert send right for MachBroker server port: "
+                 << MachErrorCode(kr);
       return false;
     }
 
@@ -90,35 +96,33 @@ class MachListenerThreadDelegate : public base::PlatformThread::Delegate {
     msg.header.msgh_size = sizeof(msg);
     msg.header.msgh_local_port = server_port_.get();
 
-    const mach_msg_option_t options = MACH_RCV_MSG |
-        MACH_RCV_TRAILER_TYPE(MACH_RCV_TRAILER_AUDIT) |
-        MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AUDIT);
-
     kern_return_t kr;
-    while ((kr = mach_msg(&msg.header,
-                          options,
-                          0,
-                          sizeof(msg),
-                          server_port_,
-                          MACH_MSG_TIMEOUT_NONE,
-                          MACH_PORT_NULL)) == KERN_SUCCESS) {
+    do {
       // Use the kernel audit information to make sure this message is from
       // a task that this process spawned. The kernel audit token contains the
       // unspoofable pid of the task that sent the message.
-      //
-      // TODO(rsesek): In the 10.7 SDK, there's audit_token_to_pid().
-      pid_t child_pid;
-      audit_token_to_au32(msg.trailer.msgh_audit,
-          NULL, NULL, NULL, NULL, NULL, &child_pid, NULL, NULL);
-
-      mach_port_t child_task_port = msg.child_task_port.name;
-
-      // Take the lock and update the broker information.
-      base::AutoLock lock(broker_->GetLock());
-      broker_->FinalizePid(child_pid, child_task_port);
-    }
-
-    MACH_LOG(ERROR, kr) << "mach_msg";
+      mach_msg_option_t options = MACH_RCV_MSG |
+          MACH_RCV_TRAILER_TYPE(MACH_RCV_TRAILER_AUDIT) |
+          MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AUDIT);
+
+      kr = mach_msg(&msg.header, options, 0, sizeof(msg), server_port_,
+          MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+      if (kr == KERN_SUCCESS) {
+        // TODO(rsesek): In the 10.7 SDK, there's audit_token_to_pid().
+        pid_t child_pid;
+        audit_token_to_au32(msg.trailer.msgh_audit,
+            NULL, NULL, NULL, NULL, NULL, &child_pid, NULL, NULL);
+
+        mach_port_t child_task_port = msg.child_task_port.name;
+
+        // Take the lock and update the broker information.
+        base::AutoLock lock(broker_->GetLock());
+        broker_->FinalizePid(child_pid, child_task_port);
+      }
+    } while (kr == KERN_SUCCESS);
+
+    LOG(ERROR) << "MachBroker thread exiting; mach_msg() likely failed: "
+               << MachErrorCode(kr);
   }
 
  private:
@@ -137,7 +141,7 @@ bool MachBroker::ChildSendTaskPortToParent() {
   mach_port_t bootstrap_port;
   kern_return_t kr = task_get_bootstrap_port(mach_task_self(), &bootstrap_port);
   if (kr != KERN_SUCCESS) {
-    MACH_LOG(ERROR, kr) << "task_get_bootstrap_port";
+    LOG(ERROR) << "Failed to look up bootstrap port: " << MachErrorCode(kr);
     return false;
   }
 
@@ -145,7 +149,7 @@ bool MachBroker::ChildSendTaskPortToParent() {
   kr = bootstrap_look_up(bootstrap_port,
       const_cast<char*>(GetMachPortName().c_str()), &parent_port);
   if (kr != KERN_SUCCESS) {
-    BOOTSTRAP_LOG(ERROR, kr) << "bootstrap_look_up";
+    LOG(ERROR) << "Failed to look up named parent port: " << MachErrorCode(kr);
     return false;
   }
 
@@ -165,7 +169,7 @@ bool MachBroker::ChildSendTaskPortToParent() {
   kr = mach_msg(&msg.header, MACH_SEND_MSG | MACH_SEND_TIMEOUT, sizeof(msg),
       0, MACH_PORT_NULL, 100 /*milliseconds*/, MACH_PORT_NULL);
   if (kr != KERN_SUCCESS) {
-    MACH_LOG(ERROR, kr) << "mach_msg";
+    LOG(ERROR) << "Failed to send task port to parent: " << MachErrorCode(kr);
     return false;
   }
 
@@ -275,7 +279,9 @@ void MachBroker::InvalidatePid(base::ProcessHandle pid) {
 
   kern_return_t kr = mach_port_deallocate(mach_task_self(),
                                           it->second);
-  MACH_LOG_IF(WARNING, kr != KERN_SUCCESS, kr) << "mach_port_deallocate";
+  LOG_IF(WARNING, kr != KERN_SUCCESS)
+     << "Failed to mach_port_deallocate mach task " << it->second
+     << ", error " << MachErrorCode(kr);
   mach_map_.erase(it);
 }