Renderers should immediately exit on failure to send an IPC to the browser.

content/renderer/render_thread_impl.cc

 // Copyright (c) 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.
 
 #include "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <utility>
@@ skipping 956 matching lines @@
     }
   }
 
   if (pumping_events) {
     renderer_scheduler_->SuspendTimerQueue();
     WebView::willEnterModalLoop();
   }
 
   bool rv = ChildThreadImpl::Send(msg);
 
+  // In the fast shutdown path, the browser kills the IPC channel without
+  // informing the renderer. This means that any IPC message might fail. Either
+  // every sender of any IPC message needs to gracefully handle failures, or
+  // else the process needs to exit immediately. Since the renderer is no longer
+  // expected to have any user-visible effects, or make any persistent changes,
+  // exit immediately. https://crbug.com/615121.
+  if (!rv)
+    exit(EXIT_SUCCESS);

[jam, 2016/06/06 20:25:52]

seems like this should match exit(0) in SuicideOnChannelErrorFilter . I realize
both are 0, but we should be consistent in both of them.

Why isn't this in ChildThreadImpl::Send so that it's done for all child
processes instead of just renderers?

With this change,
https://codereview.chromium.org/2028833003/diff/60001/content/child/child_sha...
should that move to thread_safe_sender.cc's Send method instead?

+
   if (pumping_events) {
     WebView::didExitModalLoop();
     renderer_scheduler_->ResumeTimerQueue();
   }
 
   return rv;
 }
 
 IPC::SyncChannel* RenderThreadImpl::GetChannel() {
   return channel();
@@ skipping 1104 matching lines @@
       v8_memory_pressure_level == v8::MemoryPressureLevel::kCritical)
     v8_memory_pressure_level = v8::MemoryPressureLevel::kModerate;
 
   blink::mainThreadIsolate()->MemoryPressureNotification(
       v8_memory_pressure_level);
   blink::MemoryPressureNotificationToWorkerThreadIsolates(
       v8_memory_pressure_level);
 }
 
 }  // namespace content