Pass StatsTable shared memory via global descriptors on Posix rather than using named shared memory.

content/browser/child_process_launcher.cc

Index: content/browser/child_process_launcher.cc
diff --git a/content/browser/child_process_launcher.cc b/content/browser/child_process_launcher.cc
index b5bb3f491f070688914d8f2f8146969509e341db..876fd938f9ec25601b93ea2e3193db55cfa61a58 100644
--- a/content/browser/child_process_launcher.cc
+++ b/content/browser/child_process_launcher.cc
@@ -32,12 +32,14 @@
 #include "base/android/jni_android.h"
 #include "content/browser/android/child_process_launcher_android.h"
 #elif defined(OS_POSIX)
+#include "base/memory/shared_memory.h"
 #include "base/memory/singleton.h"
 #include "content/browser/renderer_host/render_sandbox_host_linux.h"
 #include "content/browser/zygote_host/zygote_host_impl_linux.h"
 #endif
 
 #if defined(OS_POSIX)
+#include "base/metrics/stats_table.h"
 #include "base/posix/global_descriptors.h"
 #endif
 
@@ -206,7 +208,13 @@ class ChildProcessLauncher::Context
     std::vector<FileDescriptorInfo> files_to_register;
     files_to_register.push_back(
         FileDescriptorInfo(kPrimaryIPCChannel,
-                                    base::FileDescriptor(ipcfd, false)));
+                           base::FileDescriptor(ipcfd, false)));
+    base::StatsTable* stats_table = base::StatsTable::current();
+    if (stats_table &&
+        base::SharedMemory::IsHandleValid(stats_table->GetSharedMemoryHandle()))
+      files_to_register.push_back(

[jar (doing other things), 2013/08/23 00:24:04]

nit: <sadly>: When the body for an if() extends across more than one line (lines
215-217), you need to put curlies around it.  This means you'll need to wrap 214
some more to make room for the curly (sorry).

[rmcilroy, 2013/08/23 17:03:30]

Dang, thought that might be the case :).  Done

+          FileDescriptorInfo(kStatsTableSharedMemFd,
+                             stats_table->GetSharedMemoryHandle()));
 
     GetContentClient()->browser()->
         GetAdditionalMappedFilesForChildProcess(*cmd_line, child_process_id,
@@ -227,8 +235,13 @@ class ChildProcessLauncher::Context
     std::vector<FileDescriptorInfo> files_to_register;
     files_to_register.push_back(
         FileDescriptorInfo(kPrimaryIPCChannel,
-                                    base::FileDescriptor(ipcfd, false)));
-
+                           base::FileDescriptor(ipcfd, false)));
+    base::StatsTable* stats_table = base::StatsTable::current();
+    if (stats_table &&
+        base::SharedMemory::IsHandleValid(stats_table->GetSharedMemoryHandle()))

[jar (doing other things), 2013/08/23 00:24:04]

nit: add curlies here too.

[rmcilroy, 2013/08/23 17:03:30]

Done.

+      files_to_register.push_back(
+          FileDescriptorInfo(kStatsTableSharedMemFd,
+                             stats_table->GetSharedMemoryHandle()));
 #if !defined(OS_MACOSX)
     GetContentClient()->browser()->
         GetAdditionalMappedFilesForChildProcess(*cmd_line, child_process_id,