IPC::Message -> base::Pickle

This changes consumers of IPC::Message to generally refer
refer to base::Pickle instead when performing serialization
and deserialization operations. The few specific instances
where the IPC::Message interface (Read/WriteAttachent) is
needed can safely be static_cast'd, as IPC::Message is the
only public subclass of base::Pickle.

The purpose of this change is to facilitate the transition
to Mojo IPC, as we've trained the Mojo bindings layer to
use existing ParamTraits<T> parameterized over base::Pickle.

To support this base::Pickle has had some stub interfaces
added for WriteAttachment and ReadAttachment, along with a
Pickle::Attachment.

A follow-up patch will add sizing traits to the standard
IPC_STRUCT macros, enabling the majority of Chrome IPC
structs to be carried over Mojo message pipes as-is.

BUG=577685
R=jam@chromium.org

Review URL: https://codereview.chromium.org/1659003003

Cr-Commit-Position: refs/heads/master@{#373323}

7 files changed, 14 insertions, 16 deletions

diff --git a/extensions/common/permissions/api_permission.cc b/extensions/common/permissions/api_permission.cc
index 89eaea5..77a1317 100644
--- a/extensions/common/permissions/api_permission.cc
+++ b/extensions/common/permissions/api_permission.cc
@@ -69,9 +69,9 @@ class SimpleAPIPermission : public APIPermission {
     return new SimpleAPIPermission(info());
   }
 
-  void Write(IPC::Message* m) const override {}
+  void Write(base::Pickle* m) const override {}
 
-  bool Read(const IPC::Message* m, base::PickleIterator* iter) override {
+  bool Read(const base::Pickle* m, base::PickleIterator* iter) override {
     return true;
   }
 
diff --git a/extensions/common/permissions/api_permission.h b/extensions/common/permissions/api_permission.h
index 5d46ce9..0b6f1a3 100644
--- a/extensions/common/permissions/api_permission.h
+++ b/extensions/common/permissions/api_permission.h
@@ -324,10 +324,10 @@ class APIPermission {
 
   // IPC functions
   // Writes this into the given IPC message |m|.
-  virtual void Write(IPC::Message* m) const = 0;
+  virtual void Write(base::Pickle* m) const = 0;
 
   // Reads from the given IPC message |m|.
-  virtual bool Read(const IPC::Message* m, base::PickleIterator* iter) = 0;
+  virtual bool Read(const base::Pickle* m, base::PickleIterator* iter) = 0;
 
   // Logs this permission.
   virtual void Log(std::string* log) const = 0;
diff --git a/extensions/common/permissions/manifest_permission.cc b/extensions/common/permissions/manifest_permission.cc
index a3ba98e..9742138 100644
--- a/extensions/common/permissions/manifest_permission.cc
+++ b/extensions/common/permissions/manifest_permission.cc
@@ -27,14 +27,14 @@ bool ManifestPermission::Equal(const ManifestPermission* rhs) const {
   return ToValue()->Equals(rhs->ToValue().get());
 }
 
-void ManifestPermission::Write(IPC::Message* m) const {
+void ManifestPermission::Write(base::Pickle* m) const {
   base::ListValue singleton;
   base::Value* value = ToValue().release();
   singleton.Append(value);
   IPC::WriteParam(m, singleton);
 }
 
-bool ManifestPermission::Read(const IPC::Message* m,
+bool ManifestPermission::Read(const base::Pickle* m,
                               base::PickleIterator* iter) {
   base::ListValue singleton;
   if (!IPC::ReadParam(m, iter, &singleton))
diff --git a/extensions/common/permissions/manifest_permission.h b/extensions/common/permissions/manifest_permission.h
index 67c41d5..db8f07c 100644
--- a/extensions/common/permissions/manifest_permission.h
+++ b/extensions/common/permissions/manifest_permission.h
@@ -69,10 +69,10 @@ class ManifestPermission {
 
   // IPC functions
   // Writes this into the given IPC message |m|.
-  void Write(IPC::Message* m) const;
+  void Write(base::Pickle* m) const;
 
   // Reads from the given IPC message |m|.
-  bool Read(const IPC::Message* m, base::PickleIterator* iter);
+  bool Read(const base::Pickle* m, base::PickleIterator* iter);
 
   // Logs this permission.
   void Log(std::string* log) const;
diff --git a/extensions/common/permissions/set_disjunction_permission.h b/extensions/common/permissions/set_disjunction_permission.h
index 1e124ab..0e97e9d 100644
--- a/extensions/common/permissions/set_disjunction_permission.h
+++ b/extensions/common/permissions/set_disjunction_permission.h
@@ -147,11 +147,9 @@ class SetDisjunctionPermission : public APIPermission {
     return scoped_ptr<base::Value>(list);
   }
 
-  void Write(IPC::Message* m) const override {
-    IPC::WriteParam(m, data_set_);
-  }
+  void Write(base::Pickle* m) const override { IPC::WriteParam(m, data_set_); }
 
-  bool Read(const IPC::Message* m, base::PickleIterator* iter) override {
+  bool Read(const base::Pickle* m, base::PickleIterator* iter) override {
     return IPC::ReadParam(m, iter, &data_set_);
   }
 
diff --git a/extensions/common/permissions/settings_override_permission.cc b/extensions/common/permissions/settings_override_permission.cc
index 7756c5e..43765d2 100644
--- a/extensions/common/permissions/settings_override_permission.cc
+++ b/extensions/common/permissions/settings_override_permission.cc
@@ -84,9 +84,9 @@ APIPermission* SettingsOverrideAPIPermission::Intersect(
   return new SettingsOverrideAPIPermission(info(), setting_value_);
 }
 
-void SettingsOverrideAPIPermission::Write(IPC::Message* m) const {}
+void SettingsOverrideAPIPermission::Write(base::Pickle* m) const {}
 
-bool SettingsOverrideAPIPermission::Read(const IPC::Message* m,
+bool SettingsOverrideAPIPermission::Read(const base::Pickle* m,
                                          base::PickleIterator* iter) {
   return true;
 }
diff --git a/extensions/common/permissions/settings_override_permission.h b/extensions/common/permissions/settings_override_permission.h
index 32dc8b3..81a2730 100644
--- a/extensions/common/permissions/settings_override_permission.h
+++ b/extensions/common/permissions/settings_override_permission.h
@@ -33,8 +33,8 @@ class SettingsOverrideAPIPermission : public APIPermission {
   APIPermission* Diff(const APIPermission* rhs) const override;
   APIPermission* Union(const APIPermission* rhs) const override;
   APIPermission* Intersect(const APIPermission* rhs) const override;
-  void Write(IPC::Message* m) const override;
-  bool Read(const IPC::Message* m, base::PickleIterator* iter) override;
+  void Write(base::Pickle* m) const override;
+  bool Read(const base::Pickle* m, base::PickleIterator* iter) override;
   void Log(std::string* log) const override;
 
  private: