Use mojo for Chrome Loading, Part 1

content/browser/loader/resource_message_filter.cc

Index: content/browser/loader/resource_message_filter.cc
diff --git a/content/browser/loader/resource_message_filter.cc b/content/browser/loader/resource_message_filter.cc
index 186bf66316ef0ebe2a3f3df44d01520e9d2146bd..3e0613108d1f0fac0d4748eedc89cbe89364187d 100644
--- a/content/browser/loader/resource_message_filter.cc
+++ b/content/browser/loader/resource_message_filter.cc
@@ -64,7 +64,35 @@ const HostZoomMap* ResourceMessageFilter::GetHostZoomMap() const {
   return NULL;
 }
 
+bool ResourceMessageFilter::Send(IPC::Message* message) {
+  if (message->is_sync()) {
+    // We don't support sending synchronous messages from the browser.  If we
+    // really needed it, we can make this class derive from SyncMessageFilter
+    // but it seems better to not allow sending synchronous messages from the
+    // browser, since it might allow a corrupt/malicious renderer to hang us.

[jam, 2016/05/13 00:55:05]

no need for the second part of this comment, we don't send sync IPCs from the
browser period for the given reasons (there's an exception for android webview
but that's because it has to support existing android APIs).

[yhirano, 2016/05/17 12:38:49]

Done.

+    NOTREACHED() << "Can't send sync message through ResourceMessageFilter!";
+    return false;
+  }
+
+  if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(base::IgnoreResult(&ResourceMessageFilter::Send), this,
+                   message));
+    return true;
+  }
+
+  if (ResourceDispatcherHostImpl::Get()->SendWithMojoIfPossible(*message,
+                                                                this)) {
+    delete message;
+    return true;
+  }
+
+  return BrowserMessageFilter::Send(message);
+}
+
 base::WeakPtr<ResourceMessageFilter> ResourceMessageFilter::GetWeakPtr() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   return weak_ptr_factory_.GetWeakPtr();
 }