Have each SandboxedProcessLauncherDelegate maintain a zygote.

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 181 matching lines @@
 #include "sandbox/win/src/sandbox_policy.h"
 #include "ui/gfx/win/dpi.h"
 #endif
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 #include "content/browser/bootstrap_sandbox_manager_mac.h"
 #include "content/browser/browser_io_surface_manager_mac.h"
 #include "content/browser/mach_broker_mac.h"
 #endif
 
+#if defined(OS_POSIX)
+#include "content/browser/zygote_host/zygote_communication_linux.h"
+#include "content/browser/zygote_host/zygote_host_impl_linux.h"
+#endif  // defined(OS_POSIX)
+
 #if defined(USE_OZONE)
 #include "ui/ozone/public/client_native_pixmap_factory.h"
 #include "ui/ozone/public/ozone_platform.h"
 #include "ui/ozone/public/ozone_switches.h"
 #endif
 
 #if defined(ENABLE_BROWSER_CDMS)
 #include "content/browser/media/cdm/browser_cdm_manager.h"
 #endif
 
@@ skipping 168 matching lines @@
     const base::string16& sid =
         GetContentClient()->browser()->GetAppContainerSidForSandboxType(
             GetSandboxType());
     if (!sid.empty())
       AddAppContainerPolicy(policy, sid.c_str());
 
     return GetContentClient()->browser()->PreSpawnRenderer(policy);
   }
 
 #elif defined(OS_POSIX)
-  bool ShouldUseZygote() override {
+  ZygoteHandle* GetZygote() override {
     const base::CommandLine& browser_command_line =
         *base::CommandLine::ForCurrentProcess();
     base::CommandLine::StringType renderer_prefix =
         browser_command_line.GetSwitchValueNative(switches::kRendererCmdPrefix);
-    return renderer_prefix.empty();
+    if (renderer_prefix.empty()) {
+      static ZygoteHandle zygote;
+#if !defined(OS_MACOSX) && !defined(OS_ANDROID)

[mdempsky, 2015/12/22 21:21:33]

We don't need the GetZygote function on OS X or Android anyway, so you could
also just completely #ifdef-out GetZygote on those platforms.  That would
actually be desirable too if it's not much trouble, because the linker can't do
dead code elimination on unused virtual functions (to my knowledge).

(Note: We do still need GetEnvironment and TakeIpcFd on OS X, but not on
Android.)

[Greg K, 2016/01/05 21:42:13]

Done.

+      if (zygote == nullptr) {
+        zygote = new ZygoteCommunication();
+        zygote->Init();
+        ZygoteHostImpl::GetInstance()->SetRendererSandboxStatus(

[mdempsky, 2015/12/22 21:21:33]

This is kind of clunky, though I don't have a better concrete suggestion off
hand.

I'm wondering if we could make the ZygoteHandle visible externally as a static
RenderProcessHostImpl::zygote_ or something, and then other code could directly
use RenderProcessHostImpl::zygote_->GetSandboxStatus(), but that might have race
conditions.  Hrm.

I'd suggest at least adding a TODO(kerrnel) or TODO(mdempsky) to investigate
later.

[Greg K, 2016/01/05 21:42:13]

Done.

+            zygote->GetSandboxStatus());
+      }
+#endif  // !OS_MACOSX && !defined(OS_ANDROID)
+      return &zygote;
+    }
+    return nullptr;
   }
   base::ScopedFD TakeIpcFd() override { return std::move(ipc_fd_); }
 #endif  // OS_WIN
 
   SandboxType GetSandboxType() override { return SANDBOX_TYPE_RENDERER; }
 
  private:
 #if defined(OS_POSIX)
   base::ScopedFD ipc_fd_;
 #endif  // OS_POSIX
@@ skipping 2259 matching lines @@
 void RenderProcessHostImpl::GetAudioOutputControllers(
     const GetAudioOutputControllersCallback& callback) const {
   audio_renderer_host()->GetOutputControllers(callback);
 }
 
 BluetoothDispatcherHost* RenderProcessHostImpl::GetBluetoothDispatcherHost() {
   return bluetooth_dispatcher_host_.get();
 }
 
 }  // namespace content