Delegating the "are images allowed" decision to renderer.

chrome/common/render_messages.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.
 
 // Multiply-included file, no traditional include guard.
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 // TODO(erg): This list has been temporarily annotated by erg while doing work
 // on which headers to pull out.
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "base/string16.h"
 #include "base/stringprintf.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "chrome/common/common_param_traits.h"
+#include "chrome/common/content_settings.h"
+#include "chrome/common/content_settings_pattern.h"
 #include "chrome/common/instant_types.h"
 #include "chrome/common/nacl_types.h"
 #include "chrome/common/search_provider.h"
 #include "chrome/common/thumbnail_score.h"
 #include "chrome/common/translate_errors.h"
 #include "content/common/common_param_traits.h"
 #include "content/common/webkit_param_traits.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_platform_file.h"
 #include "third_party/skia/include/core/SkBitmap.h"
@@ skipping 63 matching lines @@
 #endif  // defined(OS_POSIX) && !defined(USE_AURA)
 
 template <>
 struct ParamTraits<ContentSettings> {
   typedef ContentSettings param_type;
   static void Write(Message* m, const param_type& p);
   static bool Read(const Message* m, void** iter, param_type* r);
   static void Log(const param_type& p, std::string* l);
 };
 
+template <>
+struct ParamTraits<ContentSettingsPattern> {

[Bernhard Bauer, 2011/10/17 13:13:19]

I think you could do this via the |IPC_STRUCT_TRAITS_| macros like below
(directly serializing the parts of the parsed pattern instead of stringifying
and re-parsing it). 

[marja, 2011/10/18 12:23:02]

Done. But, I had to make ContentSettingsPattern::PatternParts, parts_ and
is_valid_ public, to be able to do this. Is that ok? It also exposes the
internal structure of ContentSettingsPattern, whereas the previous solution
assumed that they can be converted to strings and back without losing
information. Not sure which is more elegant.

[Bernhard Bauer, 2011/10/18 13:14:31]

Making ContentSettingsPattern::PatternParts itself public is fine. |parts_| and
|is_valid_| shouldn't be public. I mainly want to use the macros for
ContentSettingsPattern::PatternParts (to avoid repetition), so you could declare
ParamTraits<ContentSettingsPattern> here and then serialize the PatternParts in
the implementation (declaring IPC::ParamTraits<ContentSettingsPattern> a
friend)?

[marja, 2011/10/19 16:56:35]

(This got resolved by your CL.)

+  typedef ContentSettingsPattern param_type;
+  static void Write(Message* m, const param_type& p);
+  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
 }  // namespace IPC
 
 #endif  // CHROME_COMMON_RENDER_MESSAGES_H_
 
 #define IPC_MESSAGE_START ChromeMsgStart
 
 IPC_ENUM_TRAITS(ChromeViewHostMsg_GetPluginInfo_Status::Value)
 IPC_ENUM_TRAITS(InstantCompleteBehavior)
 IPC_ENUM_TRAITS(search_provider::OSDDType)
 IPC_ENUM_TRAITS(search_provider::InstallState)
@@ skipping 94 matching lines @@
 IPC_MESSAGE_CONTROL2(ChromeViewMsg_SetContentSettingsForCurrentURL,
                      GURL /* url */,
                      ContentSettings /* content_settings */)
 
 // Set the content settings for a particular url that the renderer is in the
 // process of loading.  This will be stored, to be used if the load commits
 // and ignored otherwise.
 IPC_MESSAGE_CONTROL1(ChromeViewMsg_SetDefaultContentSettings,
                      ContentSettings /* content_settings */)
 
+// Set the content settings for images.
+IPC_MESSAGE_CONTROL1(ChromeViewMsg_SetImageSettingRules,
+                     ContentSettingsForOneType /* rules */)
+
 // Tells the render view to load all blocked plugins.
 IPC_MESSAGE_ROUTED0(ChromeViewMsg_LoadBlockedPlugins)
 
 // Asks the renderer to send back stats on the WebCore cache broken down by
 // resource types.
 IPC_MESSAGE_CONTROL0(ChromeViewMsg_GetCacheResourceStats)
 
 // Asks the renderer to send back Histograms.
 IPC_MESSAGE_CONTROL1(ChromeViewMsg_GetRendererHistograms,
                      int /* sequence number of Renderer Histograms. */)
@@ skipping 367 matching lines @@
 // previous SetCookie message to be processed.
 IPC_SYNC_MESSAGE_ROUTED2_1(ChromeViewHostMsg_GetCookies,
                            GURL /* url */,
                            GURL /* first_party_for_cookies */,
                            std::string /* cookies */)
 
 // Provide the browser process with current renderer framerate.
 IPC_MESSAGE_CONTROL2(ChromeViewHostMsg_FPS,
                      int /* routing id */,
                      float /* frames per second */)