[Mac] Log stack trace for CHECK in bug 97285.

content/renderer/plugin_channel_host.cc

 // Copyright (c) 2011 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/plugin_channel_host.h"
 
 #include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "content/common/child_process.h"
 #include "content/common/npobject_base.h"
 #include "content/common/plugin_messages.h"
 
 #if defined(OS_POSIX)
 #include "ipc/ipc_channel_posix.h"
 #endif
 
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebBindings.h"
 
+// TODO(shess): Debugging for http://crbug.com/97285
+//
+// The hypothesis at #55 requires that RemoveRoute() be called between
+// sending ViewHostMsg_OpenChannelToPlugin to the browser, and calling
+// GetPluginChannelHost() on the result.  This code detects that case
+// and stores the backtrace of the RemoveRoute() in a breakpad key.
+// The specific RemoveRoute() is not tracked (there could be multiple,
+// and which is the one can't be known until the open completes), but
+// the backtrace from any such nested call should be sufficient to
+// drive a repro.
+#if defined(OS_MACOSX)
+#include "base/debug/stack_trace.h"
+#include "base/mac/crash_logging.h"
+#include "base/sys_string_conversions.h"
+
+namespace {
+
+// Breakpad key for the RemoveRoute() backtrace.
+const char* kRemoveRouteTraceKey = "remove_route_bt";
+
+// GetRemoveTrackingFlag() exposes this so that
+// WebPluginDelegateProxy::Initialize() can do scoped set/reset.  When
+// true, RemoveRoute() knows WBDP::Initialize() is on the stack, and
+// records the backtrace.
+bool remove_tracking = false;
+
+}  // namespace
+#endif
+
 // A simple MessageFilter that will ignore all messages and respond to sync
 // messages with an error when is_listening_ is false.
 class IsListeningFilter : public IPC::ChannelProxy::MessageFilter {
  public:
   IsListeningFilter() : channel_(NULL) {}
 
   // MessageFilter overrides
   virtual void OnFilterRemoved() {}
   virtual void OnFilterAdded(IPC::Channel* channel) { channel_ = channel;  }
   virtual bool OnMessageReceived(const IPC::Message& message);
@@ skipping 34 matching lines @@
 // static
 bool PluginChannelHost::IsListening() {
   return IsListeningFilter::is_listening_;
 }
 
 // static
 void PluginChannelHost::SetListening(bool flag) {
   IsListeningFilter::is_listening_ = flag;
 }
 
+#if defined(OS_MACOSX)
+// static
+bool* PluginChannelHost::GetRemoveTrackingFlag() {
+  return &remove_tracking;
+}
+#endif
+
+// static
 PluginChannelHost* PluginChannelHost::GetPluginChannelHost(
     const IPC::ChannelHandle& channel_handle,
     base::MessageLoopProxy* ipc_message_loop) {
   PluginChannelHost* result =
       static_cast<PluginChannelHost*>(NPChannelBase::GetChannel(
           channel_handle,
           IPC::Channel::MODE_CLIENT,
           ClassFactory,
           ipc_message_loop,
           true,
@@ skipping 27 matching lines @@
 void PluginChannelHost::AddRoute(int route_id,
                                  IPC::Channel::Listener* listener,
                                  NPObjectBase* npobject) {
   NPChannelBase::AddRoute(route_id, listener, npobject);
 
   if (!npobject)
     proxies_[route_id] = listener;
 }
 
 void PluginChannelHost::RemoveRoute(int route_id) {
+#if defined(OS_MACOSX)
+  if (remove_tracking) {
+    base::debug::StackTrace trace;
+    size_t count = 0;
+    const void* const* addresses = trace.Addresses(&count);
+    base::mac::SetCrashKeyFromAddresses(
+        base::SysUTF8ToNSString(kRemoveRouteTraceKey), addresses, count);
+  }
+#endif
+
   proxies_.erase(route_id);
   NPChannelBase::RemoveRoute(route_id);
 }
 
 bool PluginChannelHost::OnControlMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PluginChannelHost, message)
     IPC_MESSAGE_HANDLER(PluginHostMsg_SetException, OnSetException)
     IPC_MESSAGE_HANDLER(PluginHostMsg_PluginShuttingDown, OnPluginShuttingDown)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ skipping 24 matching lines @@
 void PluginChannelHost::OnChannelError() {
   NPChannelBase::OnChannelError();
 
   for (ProxyMap::iterator iter = proxies_.begin();
        iter != proxies_.end(); iter++) {
     iter->second->OnChannelError();
   }
 
   proxies_.clear();
 }