Make it easier to create new IPC channel types (i.e. renderer/plugin). Inste...

chrome/common/ipc_message_utils.h

Index: chrome/common/ipc_message_utils.h
===================================================================
--- chrome/common/ipc_message_utils.h	(revision 9103)
+++ chrome/common/ipc_message_utils.h	(working copy)
@@ -34,70 +34,43 @@
 struct WebApplicationInfo;
 }  // namespace webkit_glue
 
-namespace IPC {
+// Used by IPC_BEGIN_MESSAGES so that each message class starts from a unique
+// base.  Messages have unique IDs across channels in order for the IPC logging
+// code to figure out the message class from its ID.
+enum IPCMessageStart {
+  // By using a start value of 0 for automation messages, we keep backward
+  // compatibility with old builds.
+  AutomationMsgStart = 0,
+  ViewMsgStart,
+  ViewHostMsgStart,
+  PluginProcessMsgStart,
+  PluginProcessHostMsgStart,
+  PluginMsgStart,
+  PluginHostMsgStart,
+  NPObjectMsgStart,
+  TestMsgStart,
+  // NOTE: When you add a new message class, also update
+  // IPCStatusView::IPCStatusView to ensure logging works.
+  // NOTE: this enum is used by IPC_MESSAGE_MACRO to generate a unique message
+  // id.  Only 4 bits are used for the message type, so if this enum needs more
+  // than 16 entries, that code needs to be updated.
+  LastMsgIndex
+};
 
-// Used by the message macros to register a logging function based on the
-// message class.
-typedef void (LogFunction)(uint16 type,
-                           std::wstring* name,
-                           const IPC::Message* msg,
-                           std::wstring* params);
-void RegisterMessageLogger(int msg_start, LogFunction* func);
+COMPILE_ASSERT(LastMsgIndex <= 16, need_to_update_IPC_MESSAGE_MACRO);
 
-
 //-----------------------------------------------------------------------------
-// An iterator class for reading the fields contained within a Message.
-
-class MessageIterator {
- public:
-  explicit MessageIterator(const Message& m) : msg_(m), iter_(NULL) {
-  }
-  int NextInt() const {
-    int val;
-    if (!msg_.ReadInt(&iter_, &val))
-      NOTREACHED();
-    return val;
-  }
-  intptr_t NextIntPtr() const {
-    intptr_t val;
-    if (!msg_.ReadIntPtr(&iter_, &val))
-      NOTREACHED();
-    return val;
-  }
-  const std::string NextString() const {
-    std::string val;
-    if (!msg_.ReadString(&iter_, &val))
-      NOTREACHED();
-    return val;
-  }
-  const std::wstring NextWString() const {
-    std::wstring val;
-    if (!msg_.ReadWString(&iter_, &val))
-      NOTREACHED();
-    return val;
-  }
-  const void NextData(const char** data, int* length) const {
-    if (!msg_.ReadData(&iter_, data, length)) {
-      NOTREACHED();
-    }
-  }
- private:
-  const Message& msg_;
-  mutable void* iter_;
-};
-
-//-----------------------------------------------------------------------------
 // ParamTraits specializations, etc.
 
 template <class P> struct ParamTraits {};
 
 template <class P>
-static inline void WriteParam(Message* m, const P& p) {
+static inline void WriteParam(IPC::Message* m, const P& p) {
   ParamTraits<P>::Write(m, p);
 }
 
 template <class P>
-static inline bool ReadParam(const Message* m, void** iter, P* p) {
+static inline bool ReadParam(const IPC::Message* m, void** iter, P* p) {
   return ParamTraits<P>::Read(m, iter, p);
 }
 
@@ -109,10 +82,10 @@
 template <>
 struct ParamTraits<bool> {
   typedef bool param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteBool(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadBool(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -123,10 +96,10 @@
 template <>
 struct ParamTraits<int> {
   typedef int param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteInt(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadInt(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -137,10 +110,10 @@
 template <>
 struct ParamTraits<long> {
   typedef long param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteLong(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadLong(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -151,10 +124,10 @@
 template <>
 struct ParamTraits<size_t> {
   typedef size_t param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteSize(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadSize(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -168,10 +141,10 @@
 template <>
 struct ParamTraits<uint32> {
   typedef uint32 param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteUInt32(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadUInt32(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -183,10 +156,10 @@
 template <>
 struct ParamTraits<int64> {
   typedef int64 param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteInt64(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadInt64(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -197,10 +170,10 @@
 template <>
 struct ParamTraits<uint64> {
   typedef uint64 param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteInt64(static_cast<int64>(p));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadInt64(iter, reinterpret_cast<int64*>(r));
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -211,10 +184,10 @@
 template <>
 struct ParamTraits<double> {
   typedef double param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteData(reinterpret_cast<const char*>(&p), sizeof(param_type));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     bool result = m->ReadData(iter, &data, &data_size);
@@ -235,10 +208,10 @@
 template <>
 struct ParamTraits<wchar_t> {
   typedef wchar_t param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteData(reinterpret_cast<const char*>(&p), sizeof(param_type));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     bool result = m->ReadData(iter, &data, &data_size);
@@ -259,10 +232,10 @@
 template <>
 struct ParamTraits<base::Time> {
   typedef base::Time param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     ParamTraits<int64>::Write(m, p.ToInternalValue());
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     int64 value;
     if (!ParamTraits<int64>::Read(m, iter, &value))
       return false;
@@ -278,10 +251,10 @@
 template <>
 struct ParamTraits<LOGFONT> {
   typedef LOGFONT param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteData(reinterpret_cast<const char*>(&p), sizeof(LOGFONT));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     bool result = m->ReadData(iter, &data, &data_size);
@@ -302,10 +275,10 @@
 template <>
 struct ParamTraits<MSG> {
   typedef MSG param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteData(reinterpret_cast<const char*>(&p), sizeof(MSG));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     bool result = m->ReadData(iter, &data, &data_size);
@@ -324,11 +297,11 @@
 template <>
 struct ParamTraits<SkBitmap> {
   typedef SkBitmap param_type;
-  static void Write(Message* m, const param_type& p);
+  static void Write(IPC::Message* m, const param_type& p);
 
   // Note: This function expects parameter |r| to be of type &SkBitmap since
   // r->SetConfig() and r->SetPixels() are called.
-  static bool Read(const Message* m, void** iter, param_type* r);
+  static bool Read(const IPC::Message* m, void** iter, param_type* r);
 
   static void Log(const param_type& p, std::wstring* l);
 };
@@ -336,10 +309,10 @@
 template <>
 struct ParamTraits<std::string> {
   typedef std::string param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteString(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadString(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -350,7 +323,7 @@
 template <>
 struct ParamTraits<std::vector<unsigned char> > {
   typedef std::vector<unsigned char> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     if (p.size() == 0) {
       m->WriteData(NULL, 0);
     } else {
@@ -358,7 +331,7 @@
                    static_cast<int>(p.size()));
     }
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     if (!m->ReadData(iter, &data, &data_size) || data_size < 0)
@@ -377,14 +350,14 @@
 template <>
 struct ParamTraits<std::vector<char> > {
   typedef std::vector<char> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     if (p.size() == 0) {
       m->WriteData(NULL, 0);
     } else {
       m->WriteData(&p.front(), static_cast<int>(p.size()));
     }
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     if (!m->ReadData(iter, &data, &data_size) || data_size < 0)
@@ -403,12 +376,12 @@
 template <class P>
 struct ParamTraits<std::vector<P> > {
   typedef std::vector<P> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::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) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     int size;
     if (!m->ReadLength(iter, &size))
       return false;
@@ -442,7 +415,7 @@
 template <class K, class V>
 struct ParamTraits<std::map<K, V> > {
   typedef std::map<K, V> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, static_cast<int>(p.size()));
     typename param_type::const_iterator iter;
     for (iter = p.begin(); iter != p.end(); ++iter) {
@@ -450,7 +423,7 @@
       WriteParam(m, iter->second);
     }
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     int size;
     if (!ReadParam(m, iter, &size) || size < 0)
       return false;
@@ -472,10 +445,10 @@
 template <>
 struct ParamTraits<std::wstring> {
   typedef std::wstring param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteWString(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return m->ReadWString(iter, r);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -486,8 +459,8 @@
 template <>
 struct ParamTraits<GURL> {
   typedef GURL param_type;
-  static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, void** iter, param_type* p);
+  static void Write(IPC::Message* m, const param_type& p);
+  static bool Read(const IPC::Message* m, void** iter, param_type* p);
   static void Log(const param_type& p, std::wstring* l);
 };
 
@@ -496,10 +469,10 @@
 template <>
 struct ParamTraits<HANDLE> {
   typedef HANDLE param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteIntPtr(reinterpret_cast<intptr_t>(p));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     DCHECK_EQ(sizeof(param_type), sizeof(intptr_t));
     return m->ReadIntPtr(iter, reinterpret_cast<intptr_t*>(r));
   }
@@ -511,10 +484,10 @@
 template <>
 struct ParamTraits<HCURSOR> {
   typedef HCURSOR param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteIntPtr(reinterpret_cast<intptr_t>(p));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     DCHECK_EQ(sizeof(param_type), sizeof(intptr_t));
     return m->ReadIntPtr(iter, reinterpret_cast<intptr_t*>(r));
   }
@@ -526,10 +499,10 @@
 template <>
 struct ParamTraits<HWND> {
   typedef HWND param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteIntPtr(reinterpret_cast<intptr_t>(p));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     DCHECK_EQ(sizeof(param_type), sizeof(intptr_t));
     return m->ReadIntPtr(iter, reinterpret_cast<intptr_t*>(r));
   }
@@ -541,7 +514,7 @@
 template <>
 struct ParamTraits<HRGN> {
   typedef HRGN param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     int data_size = GetRegionData(p, 0, NULL);
     if (data_size) {
       char* bytes = new char[data_size];
@@ -552,7 +525,7 @@
       m->WriteData(NULL, 0);
     }
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     bool res = FALSE;
     const char *data;
     int data_size = 0;
@@ -574,10 +547,10 @@
 template <>
 struct ParamTraits<HACCEL> {
   typedef HACCEL param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteIntPtr(reinterpret_cast<intptr_t>(p));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     DCHECK_EQ(sizeof(param_type), sizeof(intptr_t));
     return m->ReadIntPtr(iter, reinterpret_cast<intptr_t*>(r));
   }
@@ -586,11 +559,11 @@
 template <>
 struct ParamTraits<POINT> {
   typedef POINT param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteInt(p.x);
     m->WriteInt(p.y);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     int x, y;
     if (!m->ReadInt(iter, &x) || !m->ReadInt(iter, &y))
       return false;
@@ -607,10 +580,10 @@
 template <>
 struct ParamTraits<FilePath> {
   typedef FilePath param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     ParamTraits<FilePath::StringType>::Write(m, p.value());
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     FilePath::StringType value;
     if (!ParamTraits<FilePath::StringType>::Read(m, iter, &value))
       return false;
@@ -625,44 +598,44 @@
 template <>
 struct ParamTraits<gfx::Point> {
   typedef gfx::Point param_type;
-  static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Write(IPC::Message* m, const param_type& p);
+  static bool Read(const IPC::Message* m, void** iter, param_type* r);
   static void Log(const param_type& p, std::wstring* l);
 };
 
 template <>
 struct ParamTraits<gfx::Rect> {
   typedef gfx::Rect param_type;
-  static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Write(IPC::Message* m, const param_type& p);
+  static bool Read(const IPC::Message* m, void** iter, param_type* r);
   static void Log(const param_type& p, std::wstring* l);
 };
 
 template <>
 struct ParamTraits<gfx::Size> {
   typedef gfx::Size param_type;
-  static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Write(IPC::Message* m, const param_type& p);
+  static bool Read(const IPC::Message* m, void** iter, param_type* r);
   static void Log(const param_type& p, std::wstring* l);
 };
 
 template<>
 struct ParamTraits<ThumbnailScore> {
   typedef ThumbnailScore param_type;
-  static void Write(Message* m, const param_type& p) {
-    IPC::ParamTraits<double>::Write(m, p.boring_score);
-    IPC::ParamTraits<bool>::Write(m, p.good_clipping);
-    IPC::ParamTraits<bool>::Write(m, p.at_top);
-    IPC::ParamTraits<base::Time>::Write(m, p.time_at_snapshot);
+  static void Write(IPC::Message* m, const param_type& p) {
+    ParamTraits<double>::Write(m, p.boring_score);
+    ParamTraits<bool>::Write(m, p.good_clipping);
+    ParamTraits<bool>::Write(m, p.at_top);
+    ParamTraits<base::Time>::Write(m, p.time_at_snapshot);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     double boring_score;
     bool good_clipping, at_top;
     base::Time time_at_snapshot;
-    if (!IPC::ParamTraits<double>::Read(m, iter, &boring_score) ||
-        !IPC::ParamTraits<bool>::Read(m, iter, &good_clipping) ||
-        !IPC::ParamTraits<bool>::Read(m, iter, &at_top) ||
-        !IPC::ParamTraits<base::Time>::Read(m, iter, &time_at_snapshot))
+    if (!ParamTraits<double>::Read(m, iter, &boring_score) ||
+        !ParamTraits<bool>::Read(m, iter, &good_clipping) ||
+        !ParamTraits<bool>::Read(m, iter, &at_top) ||
+        !ParamTraits<base::Time>::Read(m, iter, &time_at_snapshot))
       return false;
 
     r->boring_score = boring_score;
@@ -680,10 +653,10 @@
 template <>
 struct ParamTraits<WindowOpenDisposition> {
   typedef WindowOpenDisposition param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteInt(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     int temp;
     bool res = m->ReadInt(iter, &temp);
     *r = static_cast<WindowOpenDisposition>(temp);
@@ -697,10 +670,10 @@
 template <>
 struct ParamTraits<ConsoleMessageLevel> {
   typedef ConsoleMessageLevel param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteInt(p);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     int temp;
     bool res = m->ReadInt(iter, &temp);
     *r = static_cast<ConsoleMessageLevel>(temp);
@@ -714,13 +687,13 @@
 template <>
 struct ParamTraits<CacheManager::ResourceTypeStat> {
   typedef CacheManager::ResourceTypeStat param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.count);
     WriteParam(m, p.size);
     WriteParam(m, p.live_size);
     WriteParam(m, p.decoded_size);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     bool result =
         ReadParam(m, iter, &r->count) &&
         ReadParam(m, iter, &r->size) &&
@@ -737,14 +710,14 @@
 template <>
 struct ParamTraits<CacheManager::ResourceTypeStats> {
   typedef CacheManager::ResourceTypeStats param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.images);
     WriteParam(m, p.css_stylesheets);
     WriteParam(m, p.scripts);
     WriteParam(m, p.xsl_stylesheets);
     WriteParam(m, p.fonts);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     bool result =
       ReadParam(m, iter, &r->images) &&
       ReadParam(m, iter, &r->css_stylesheets) &&
@@ -768,10 +741,10 @@
 template <>
 struct ParamTraits<XFORM> {
   typedef XFORM param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     m->WriteData(reinterpret_cast<const char*>(&p), sizeof(XFORM));
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     const char *data;
     int data_size = 0;
     bool result = m->ReadData(iter, &data, &data_size);
@@ -793,10 +766,10 @@
 template <>
 struct ParamTraits<WebCursor> {
   typedef WebCursor param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     p.Serialize(m);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return r->Deserialize(m, iter);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -804,6 +777,8 @@
   }
 };
 
+namespace IPC {
+
 struct LogData {
   std::wstring channel;
   uint16 type;
@@ -816,10 +791,12 @@
   std::wstring params;
 };
 
+}
+
 template <>
-struct ParamTraits<LogData> {
-  typedef LogData param_type;
-  static void Write(Message* m, const param_type& p) {
+struct ParamTraits<IPC::LogData> {
+  typedef IPC::LogData param_type;
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.channel);
     WriteParam(m, static_cast<int>(p.type));
     WriteParam(m, p.flags);
@@ -828,7 +805,7 @@
     WriteParam(m, p.dispatch);
     WriteParam(m, p.params);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     int type;
     bool result =
       ReadParam(m, iter, &r->channel) &&
@@ -849,9 +826,9 @@
 template <>
 struct ParamTraits<Tuple0> {
   typedef Tuple0 param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return true;
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -861,10 +838,10 @@
 template <class A>
 struct ParamTraits< Tuple1<A> > {
   typedef Tuple1<A> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.a);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return ReadParam(m, iter, &r->a);
   }
   static void Log(const param_type& p, std::wstring* l) {
@@ -875,11 +852,11 @@
 template <class A, class B>
 struct ParamTraits< Tuple2<A, B> > {
   typedef Tuple2<A, B> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.a);
     WriteParam(m, p.b);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return (ReadParam(m, iter, &r->a) &&
             ReadParam(m, iter, &r->b));
   }
@@ -893,12 +870,12 @@
 template <class A, class B, class C>
 struct ParamTraits< Tuple3<A, B, C> > {
   typedef Tuple3<A, B, C> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.a);
     WriteParam(m, p.b);
     WriteParam(m, p.c);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return (ReadParam(m, iter, &r->a) &&
             ReadParam(m, iter, &r->b) &&
             ReadParam(m, iter, &r->c));
@@ -915,13 +892,13 @@
 template <class A, class B, class C, class D>
 struct ParamTraits< Tuple4<A, B, C, D> > {
   typedef Tuple4<A, B, C, D> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.a);
     WriteParam(m, p.b);
     WriteParam(m, p.c);
     WriteParam(m, p.d);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return (ReadParam(m, iter, &r->a) &&
             ReadParam(m, iter, &r->b) &&
             ReadParam(m, iter, &r->c) &&
@@ -941,14 +918,14 @@
 template <class A, class B, class C, class D, class E>
 struct ParamTraits< Tuple5<A, B, C, D, E> > {
   typedef Tuple5<A, B, C, D, E> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.a);
     WriteParam(m, p.b);
     WriteParam(m, p.c);
     WriteParam(m, p.d);
     WriteParam(m, p.e);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return (ReadParam(m, iter, &r->a) &&
             ReadParam(m, iter, &r->b) &&
             ReadParam(m, iter, &r->c) &&
@@ -971,7 +948,7 @@
 template <class A, class B, class C, class D, class E, class F>
 struct ParamTraits< Tuple6<A, B, C, D, E, F> > {
   typedef Tuple6<A, B, C, D, E, F> param_type;
-  static void Write(Message* m, const param_type& p) {
+  static void Write(IPC::Message* m, const param_type& p) {
     WriteParam(m, p.a);
     WriteParam(m, p.b);
     WriteParam(m, p.c);
@@ -979,7 +956,7 @@
     WriteParam(m, p.e);
     WriteParam(m, p.f);
   }
-  static bool Read(const Message* m, void** iter, param_type* r) {
+  static bool Read(const IPC::Message* m, void** iter, param_type* r) {
     return (ReadParam(m, iter, &r->a) &&
             ReadParam(m, iter, &r->b) &&
             ReadParam(m, iter, &r->c) &&
@@ -1005,13 +982,79 @@
 template <>
 struct ParamTraits<webkit_glue::WebApplicationInfo> {
   typedef webkit_glue::WebApplicationInfo param_type;
-  static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Write(IPC::Message* m, const param_type& p);
+  static bool Read(const IPC::Message* m, void** iter, param_type* r);
   static void Log(const param_type& p, std::wstring* l);
 };
 
+// Traits for ViewMsg_FindInPageMsg_Request structure to pack/unpack.
+template <>
+struct ParamTraits<FindInPageRequest> {
+  typedef FindInPageRequest param_type;
+  static void Write(IPC::Message* m, const param_type& p) {
+    WriteParam(m, p.request_id);
+    WriteParam(m, p.search_string);
+    WriteParam(m, p.forward);
+    WriteParam(m, p.match_case);
+    WriteParam(m, p.find_next);
+  }
+  static bool Read(const IPC::Message* m, void** iter, param_type* p) {
+    return
+      ReadParam(m, iter, &p->request_id) &&
+      ReadParam(m, iter, &p->search_string) &&
+      ReadParam(m, iter, &p->forward) &&
+      ReadParam(m, iter, &p->match_case) &&
+      ReadParam(m, iter, &p->find_next);
+  }
+  static void Log(const param_type& p, std::wstring* l) {
+    l->append(L"<FindInPageRequest>");
+  }
+};
 
+namespace IPC {
+
 //-----------------------------------------------------------------------------
+// An iterator class for reading the fields contained within a Message.
+
+class MessageIterator {
+ public:
+  explicit MessageIterator(const Message& m) : msg_(m), iter_(NULL) {
+  }
+  int NextInt() const {
+    int val;
+    if (!msg_.ReadInt(&iter_, &val))
+      NOTREACHED();
+    return val;
+  }
+  intptr_t NextIntPtr() const {
+    intptr_t val;
+    if (!msg_.ReadIntPtr(&iter_, &val))
+      NOTREACHED();
+    return val;
+  }
+  const std::string NextString() const {
+    std::string val;
+    if (!msg_.ReadString(&iter_, &val))
+      NOTREACHED();
+    return val;
+  }
+  const std::wstring NextWString() const {
+    std::wstring val;
+    if (!msg_.ReadWString(&iter_, &val))
+      NOTREACHED();
+    return val;
+  }
+  const void NextData(const char** data, int* length) const {
+    if (!msg_.ReadData(&iter_, data, length)) {
+      NOTREACHED();
+    }
+  }
+ private:
+  const Message& msg_;
+  mutable void* iter_;
+};
+
+//-----------------------------------------------------------------------------
 // Generic message subclasses
 
 // Used for asynchronous messages.
@@ -1025,7 +1068,7 @@
     WriteParam(this, p);
   }
 
-  static bool Read(const Message* msg, Param* p) {
+  static bool Read(const IPC::Message* msg, Param* p) {
     void* iter = NULL;
     bool rv = ReadParam(msg, &iter, p);
     DCHECK(rv) << "Error deserializing message " << msg->type();
@@ -1034,7 +1077,7 @@
 
   // Generic dispatcher.  Should cover most cases.
   template<class T, class Method>
-  static bool Dispatch(const Message* msg, T* obj, Method func) {
+  static bool Dispatch(const IPC::Message* msg, T* obj, Method func) {
     Param p;
     if (Read(msg, &p)) {
       DispatchToMethod(obj, func, p);
@@ -1047,7 +1090,7 @@
   // needs the message as well.  They assume that "Param" is a type of Tuple
   // (except the one arg case, as there is no Tuple1).
   template<class T, typename TA>
-  static bool Dispatch(const Message* msg, T* obj,
+  static bool Dispatch(const IPC::Message* msg, T* obj,
                        void (T::*func)(const Message&, TA)) {
     Param p;
     if (Read(msg, &p)) {
@@ -1058,7 +1101,7 @@
   }
 
   template<class T, typename TA, typename TB>
-  static bool Dispatch(const Message* msg, T* obj,
+  static bool Dispatch(const IPC::Message* msg, T* obj,
                        void (T::*func)(const Message&, TA, TB)) {
     Param p;
     if (Read(msg, &p)) {
@@ -1069,7 +1112,7 @@
   }
 
   template<class T, typename TA, typename TB, typename TC>
-  static bool Dispatch(const Message* msg, T* obj,
+  static bool Dispatch(const IPC::Message* msg, T* obj,
                        void (T::*func)(const Message&, TA, TB, TC)) {
     Param p;
     if (Read(msg, &p)) {
@@ -1080,7 +1123,7 @@
   }
 
   template<class T, typename TA, typename TB, typename TC, typename TD>
-  static bool Dispatch(const Message* msg, T* obj,
+  static bool Dispatch(const IPC::Message* msg, T* obj,
                        void (T::*func)(const Message&, TA, TB, TC, TD)) {
     Param p;
     if (Read(msg, &p)) {
@@ -1092,7 +1135,7 @@
 
   template<class T, typename TA, typename TB, typename TC, typename TD,
            typename TE>
-  static bool Dispatch(const Message* msg, T* obj,
+  static bool Dispatch(const IPC::Message* msg, T* obj,
                        void (T::*func)(const Message&, TA, TB, TC, TD, TE)) {
     Param p;
     if (Read(msg, &p)) {
@@ -1102,11 +1145,59 @@
     return false;
   }
 
-  static void Log(const Message* msg, std::wstring* l) {
+  static void Log(const IPC::Message* msg, std::wstring* l) {
     Param p;
     if (Read(msg, &p))
       LogParam(p, l);
   }
+
+  // Functions used to do manual unpacking.  Only used by the automation code,
+  // these should go away once that code uses SyncChannel.
+  template<typename TA, typename TB>
+  static bool Read(const IPC::Message* msg, TA* a, TB* b) {
+    ParamType params;
+    if (!Read(msg, &params))
+      return false;
+    *a = params.a;
+    *b = params.b;
+    return true;
+  }
+
+  template<typename TA, typename TB, typename TC>
+  static bool Read(const IPC::Message* msg, TA* a, TB* b, TC* c) {
+    ParamType params;
+    if (!Read(msg, &params))
+      return false;
+    *a = params.a;
+    *b = params.b;
+    *c = params.c;
+    return true;
+  }
+
+  template<typename TA, typename TB, typename TC, typename TD>
+  static bool Read(const IPC::Message* msg, TA* a, TB* b, TC* c, TD* d) {
+    ParamType params;
+    if (!Read(msg, &params))
+      return false;
+    *a = params.a;
+    *b = params.b;
+    *c = params.c;
+    *d = params.d;
+    return true;
+  }
+
+  template<typename TA, typename TB, typename TC, typename TD, typename TE>
+  static bool Read(const IPC::Message* msg, TA* a, TB* b, TC* c, TD* d, TE* e) {
+    ParamType params;
+    if (!Read(msg, &params))
+      return false;
+    *a = params.a;
+    *b = params.b;
+    *c = params.c;
+    *d = params.d;
+    *e = params.e;
+    return true;
+  }
 };
 
 // This class assumes that its template argument is a RefTuple (a Tuple with
@@ -1138,7 +1229,7 @@
     WriteParam(this, send);
   }
 
-  static void Log(const Message* msg, std::wstring* l) {
+  static void Log(const IPC::Message* msg, std::wstring* l) {
     if (msg->is_sync()) {
       SendParam p;
       void* iter = SyncMessage::GetDataIterator(msg);
@@ -1163,7 +1254,7 @@
   }
 
   template<class T, class Method>
-  static bool Dispatch(const Message* msg, T* obj, Method func) {
+  static bool Dispatch(const IPC::Message* msg, T* obj, Method func) {
     SendParam send_params;
     void* iter = GetDataIterator(msg);
     Message* reply = GenerateReply(msg);
@@ -1191,7 +1282,7 @@
   }
 
   template<class T, class Method>
-  static bool DispatchDelayReply(const Message* msg, T* obj, Method func) {
+  static bool DispatchDelayReply(const IPC::Message* msg, T* obj, Method func) {
     SendParam send_params;
     void* iter = GetDataIterator(msg);
     Message* reply = GenerateReply(msg);
@@ -1252,32 +1343,6 @@
   }
 };
 
-// Traits for ViewMsg_FindInPageMsg_Request structure to pack/unpack.
-template <>
-struct ParamTraits<FindInPageRequest> {
-  typedef FindInPageRequest param_type;
-  static void Write(Message* m, const param_type& p) {
-    WriteParam(m, p.request_id);
-    WriteParam(m, p.search_string);
-    WriteParam(m, p.forward);
-    WriteParam(m, p.match_case);
-    WriteParam(m, p.find_next);
-  }
-  static bool Read(const Message* m, void** iter, param_type* p) {
-    return
-      ReadParam(m, iter, &p->request_id) &&
-      ReadParam(m, iter, &p->search_string) &&
-      ReadParam(m, iter, &p->forward) &&
-      ReadParam(m, iter, &p->match_case) &&
-      ReadParam(m, iter, &p->find_next);
-  }
-  static void Log(const param_type& p, std::wstring* l) {
-    l->append(L"<FindInPageRequest>");
-  }
-};
-
-//-----------------------------------------------------------------------------
-
 }  // namespace IPC
 
 #endif  // CHROME_COMMON_IPC_MESSAGE_UTILS_H_