Avoid exiting the renderer process if it has a pending render view.

content/browser/renderer_host/browser_render_process_host.cc

Index: content/browser/renderer_host/browser_render_process_host.cc
diff --git a/content/browser/renderer_host/browser_render_process_host.cc b/content/browser/renderer_host/browser_render_process_host.cc
index 7222b096aa1ee70a107f712d16a55ce7e821ea76..d365b68133ceb9a5fd4122c11b08ff4244d8035c 100644
--- a/content/browser/renderer_host/browser_render_process_host.cc
+++ b/content/browser/renderer_host/browser_render_process_host.cc
@@ -187,6 +187,7 @@ class RendererURLRequestContextSelector
 BrowserRenderProcessHost::BrowserRenderProcessHost(Profile* profile)
     : RenderProcessHost(profile),
       visible_widgets_(0),
+      pending_views_(0),
       backgrounded_(true),
       ALLOW_THIS_IN_INITIALIZER_LIST(cached_dibs_cleaner_(
             base::TimeDelta::FromSeconds(5),
@@ -463,6 +464,15 @@ int BrowserRenderProcessHost::VisibleWidgetCount() const {
   return visible_widgets_;
 }
 
+void BrowserRenderProcessHost::AddPendingView() {
+  pending_views_++;
+}
+
+void BrowserRenderProcessHost::RemovePendingView() {
+  DCHECK(pending_views_);
+  pending_views_--;

[Matt Perry, 2011/05/10 01:14:50]

does this need to send a shutdown if pending_views_ reaches 0?

[Charlie Reis, 2011/05/10 01:33:09]

Nope-- it'll also reach 0 if we commit the view and have it showing.  The only
period of risk (once we do the rest of the swapping changes in the other CL) is
while it's pending.

+}
+
 void BrowserRenderProcessHost::AppendRendererCommandLine(
     CommandLine* command_line) const {
   // Pass the process type first, so it shows first in process listings.
@@ -784,6 +794,8 @@ bool BrowserRenderProcessHost::OnMessageReceived(const IPC::Message& msg) {
     // Dispatch control messages.
     bool msg_is_ok = true;
     IPC_BEGIN_MESSAGE_MAP_EX(BrowserRenderProcessHost, msg, msg_is_ok)
+      IPC_MESSAGE_HANDLER(ChildProcessHostMsg_ShutdownRequest,
+                          OnShutdownRequest)
       IPC_MESSAGE_HANDLER(ViewHostMsg_UpdatedCacheStats,
                           OnUpdatedCacheStats)
       IPC_MESSAGE_HANDLER(ViewHostMsg_SuddenTerminationChanged,
@@ -823,6 +835,10 @@ void BrowserRenderProcessHost::OnChannelConnected(int32 peer_pid) {
   Send(new ChildProcessMsg_SetIPCLoggingEnabled(
       IPC::Logging::GetInstance()->Enabled()));
 #endif
+
+  // Make sure the child checks with us before exiting, so that we do not try
+  // to schedule a new navigation in a swapped out and exiting renderer.
+  Send(new ChildProcessMsg_AskBeforeShutdown());
 }
 
 void BrowserRenderProcessHost::OnChannelError() {
@@ -878,6 +894,20 @@ void BrowserRenderProcessHost::OnChannelError() {
   // TODO(darin): clean this up
 }
 
+void BrowserRenderProcessHost::OnShutdownRequest() {
+  // Don't shutdown if there are pending RenderViews being swapped back in.
+  if (pending_views_)
+    return;
+
+  // Notify any tabs that might have swapped out renderers from this process.
+  // They should not attempt to swap them back in.
+  NotificationService::current()->Notify(
+      NotificationType::RENDERER_PROCESS_CLOSING,
+      Source<RenderProcessHost>(this), NotificationService::NoDetails());
+
+  Send(new ChildProcessMsg_Shutdown());
+}
+
 void BrowserRenderProcessHost::OnUpdatedCacheStats(
     const WebCache::UsageStats& stats) {
   WebCacheManager::GetInstance()->ObserveStats(id(), stats);