Remove weird dependency on extensions from webui.

Re-plumb extension request messages in a more sane way.

Before, each RVH had ProcessWebUIMessage(), which was
serving as a manual way of plumbing both WebUI and
extension messages to the right place, even though only
a few RVHD responded to either message.

Instead of this, we now just teach more of the stack how
to handle IPC messages in general, and delegate them up
through the stack, giving each layer a chance to handle
them if it knows how.

The result is simpler and smaller:
179 insertions(+), 252 deletions(-)

BUG=80311

Review URL: http://codereview.chromium.org/6901021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@83100 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 4 deletions

diff --git a/chrome/browser/extensions/extension_function_dispatcher.h b/chrome/browser/extensions/extension_function_dispatcher.h
index cb67988..9f91d9d 100644
--- a/chrome/browser/extensions/extension_function_dispatcher.h
+++ b/chrome/browser/extensions/extension_function_dispatcher.h
@@ -11,6 +11,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "googleurl/src/gurl.h"
+#include "ipc/ipc_channel.h"
 #include "ui/gfx/native_widget_types.h"
 
 class Browser;
@@ -20,7 +21,7 @@ class ListValue;
 class Profile;
 class RenderViewHost;
 class TabContents;
-struct ExtensionHostMsg_DomMessage_Params;
+struct ExtensionHostMsg_Request_Params;
 
 // A factory function for creating new ExtensionFunction instances.
 typedef ExtensionFunction* (*ExtensionFunctionFactory)();
@@ -28,7 +29,7 @@ typedef ExtensionFunction* (*ExtensionFunctionFactory)();
 // ExtensionFunctionDispatcher receives requests to execute functions from
 // Chromium extensions running in a RenderViewHost and dispatches them to the
 // appropriate handler. It lives entirely on the UI thread.
-class ExtensionFunctionDispatcher {
+class ExtensionFunctionDispatcher : public IPC::Channel::Listener {
  public:
   class Delegate {
    public:
@@ -85,8 +86,8 @@ class ExtensionFunctionDispatcher {
 
   Delegate* delegate() { return delegate_; }
 
-  // Handle a request to execute an extension function.
-  void HandleRequest(const ExtensionHostMsg_DomMessage_Params& params);
+  // If |message| is an extension request, handle it. Returns true if handled.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   // Send a response to a function.
   void SendResponse(ExtensionFunction* api, bool success);
@@ -121,6 +122,9 @@ class ExtensionFunctionDispatcher {
                               const Extension* extension,
                               const GURL& url);
 
+  // Message handlers.
+  void OnRequest(const ExtensionHostMsg_Request_Params& params);
+
   // We need to keep a pointer to the profile because we use it in the dtor
   // in sending EXTENSION_FUNCTION_DISPATCHER_DESTROYED, but by that point
   // the render_view_host_ has been deleted.