Use a placeholder instead of the default plugin for missing plug-ins on Mac and Linux.

ipc/ipc_message_utils.h

 // 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.
 
 #ifndef IPC_IPC_MESSAGE_UTILS_H_
 #define IPC_IPC_MESSAGE_UTILS_H_
 #pragma once
 
 #include <algorithm>
 #include <map>
@@ skipping 479 matching lines @@
     r->resize(data_size);
     if (data_size)
       memcpy(&r->front(), data, data_size);
     return true;
   }
   static void Log(const param_type& p, std::string* l) {
     LogBytes(p, l);
   }
 };
 
+template <>
+struct ParamTraits<std::vector<bool> > {

[jam, 2011/09/27 16:51:34]

why do you need this? i.e. why isn't the traits below enough?

[Bernhard Bauer, 2011/09/27 21:21:39]

std::vector has a specialization for bool which uses more compact storage
(storing eight bools in a byte), but it means that it can't return a pointer to
an individual item, and that's what the ParamTraits below uses. 

[jam, 2011/09/29 01:03:32]

what paramtraits below are you talking about? 

[Bernhard Bauer, 2011/09/29 13:20:47]

ParamTraits<std::vector<P> > takes the address of the i-th element of the vector
(line 549), and that's not possible if you have a more compact storage than one
byte per element.

[jam, 2011/09/29 16:31:10]

ah, nm now i get it. I was familiar with vector's optimization for bool, but I
thought you were doing this change for something specific in your new message.
I'm very surprised that we never sent a vector of bools before! Even if you
don't end up using it in your new IPC, of course please leave this as it'll be
useful to have.

+  typedef std::vector<bool> param_type;
+  static void Write(Message* m, const param_type& p) {
+    WriteParam(m, static_cast<int>(p.size()));
+    for (size_t i = 0; i < p.size(); i++)
+      WriteParam(m, p[i]);
+  }
+  static bool Read(const Message* m, void** iter, param_type* r) {
+    int size;
+    // ReadLength() checks for < 0 itself.
+    if (!m->ReadLength(iter, &size))
+      return false;
+    r->resize(size);
+    for (int i = 0; i < size; i++) {
+      bool value;
+      if (!ReadParam(m, iter, &value))
+        return false;
+      (*r)[i] = value;
+    }
+    return true;
+  }
+  static void Log(const param_type& p, std::string* l) {
+    for (size_t i = 0; i < p.size(); ++i) {
+      if (i != 0)
+        l->append(" ");
+      LogParam((p[i]), l);
+    }
+  }
+};
+
 template <class P>
 struct ParamTraits<std::vector<P> > {
   typedef std::vector<P> param_type;
   static void Write(Message* m, const param_type& p) {
     WriteParam(m, static_cast<int>(p.size()));
     for (size_t i = 0; i < p.size(); i++)
       WriteParam(m, p[i]);
   }
   static bool Read(const Message* m, void** iter, param_type* r) {
     int size;
@@ skipping 595 matching lines @@
     ReplyParam p(a, b, c, d, e);
     WriteParam(reply, p);
   }
 };
 
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_MESSAGE_UTILS_H_