Relanding http://src.chromium.org/viewvc/chrome?view=rev&revision=80938.

Add a new RenderViewHostObserver interface for filtering IPCs send to RenderViewHost. This is needed because with TabContentsObserver, an observer might not know which RenderViewHost a message came from duing a pending navigation. A side-benefit is that we only have to add these observers once, instead of remembering/knowing all the delegates that might want to filter these messages.

BUG=78629
Review URL: http://codereview.chromium.org/6813046

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80984 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 41 insertions, 0 deletions

diff --git a/content/browser/renderer_host/render_view_host_observer.cc b/content/browser/renderer_host/render_view_host_observer.cc
new file mode 100644
index 0000000..e60e2bb
--- /dev/null
+++ b/content/browser/renderer_host/render_view_host_observer.cc
@@ -0,0 +1,41 @@
+// 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.
+
+#include "content/browser/renderer_host/render_view_host_observer.h"
+
+#include "content/browser/renderer_host/render_view_host.h"
+
+RenderViewHostObserver::RenderViewHostObserver(RenderViewHost* render_view_host)
+    : render_view_host_(render_view_host),
+      routing_id_(render_view_host->routing_id()) {
+  render_view_host_->AddObserver(this);
+}
+
+RenderViewHostObserver::~RenderViewHostObserver() {
+  if (render_view_host_)
+    render_view_host_->RemoveObserver(this);
+}
+
+void RenderViewHostObserver::RenderViewHostDestroyed() {
+  delete this;
+}
+
+bool RenderViewHostObserver::OnMessageReceived(const IPC::Message& message) {
+  return false;
+}
+
+bool RenderViewHostObserver::Send(IPC::Message* message) {
+  if (!render_view_host_) {
+    delete message;
+    return false;
+  }
+
+  return render_view_host_->Send(message);
+}
+
+void RenderViewHostObserver::RenderViewHostDestruction() {
+  render_view_host_->RemoveObserver(this);
+  RenderViewHostDestroyed();
+  render_view_host_ = NULL;
+}