Content API changes to improve DOM stitching in ThreatDetails code.

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 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/frame_host/render_frame_host_impl.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 283 matching lines @@
     if (frame_host)
       routing_ids->insert(frame_host->GetGlobalFrameRoutingId());
     if (pending_frame_host)
       routing_ids->insert(pending_frame_host->GetGlobalFrameRoutingId());
   }
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
                           base::Bind(&NotifyRouteChangesOnIO, frame_callback,
                                      base::Passed(std::move(routing_ids))));
 }
 
+void LookupRenderFrameHostOrProxy(int process_id,
+                                  int routing_id,
+                                  RenderFrameHostImpl** rfh,
+                                  RenderFrameProxyHost** rfph) {
+  *rfph = RenderFrameProxyHost::FromID(process_id, routing_id);

[Charlie Reis, 2017/05/05 21:03:08]

nit: Let's swap the order and do rfh first, just because it's the more common
case.

[lpz, 2017/05/10 14:21:09]

Done.

+  if (*rfph == nullptr)
+    *rfh = RenderFrameHostImpl::FromID(process_id, routing_id);
+}
+
 }  // namespace
 
 // static
 RenderFrameHost* RenderFrameHost::FromID(int render_process_id,
                                          int render_frame_id) {
   return RenderFrameHostImpl::FromID(render_process_id, render_frame_id);
 }
 
 #if defined(OS_ANDROID)
 // static
@@ skipping 3207 matching lines @@
          frame_tree_node_->current_url().SchemeIs(kChromeDevToolsScheme) ||
          ChildProcessSecurityPolicyImpl::GetInstance()->HasWebUIBindings(
              GetProcess()->GetID()) ||
          // It's possible to load about:blank in a Web UI renderer.
          // See http://crbug.com/42547
          (frame_tree_node_->current_url().spec() == url::kAboutBlankURL) ||
          // InterstitialPageImpl should be the only case matching this.
          (delegate_->GetAsWebContents() == nullptr);
 }
 
+// static
+int RenderFrameHost::GetFrameTreeNodeIdForRoutingId(int process_id,
+                                                    int routing_id) {
+  RenderFrameHostImpl* rfh = nullptr;
+  RenderFrameProxyHost* rfph = nullptr;
+  LookupRenderFrameHostOrProxy(process_id, routing_id, &rfh, &rfph);
+  if (rfph) {
+    return rfph->frame_tree_node()->frame_tree_node_id();
+  } else if (rfh) {

[Charlie Reis, 2017/05/05 21:03:08]

nit: Let's swap the order and do the rfh branch first.  (Same as above.)

[lpz, 2017/05/10 14:21:09]

Done.

+    return rfh->GetFrameTreeNodeId();
+  }
+
+  return kNoFrameTreeNodeId;
+}
+
 ui::AXTreeIDRegistry::AXTreeID RenderFrameHostImpl::RoutingIDToAXTreeID(
     int routing_id) {
   RenderFrameHostImpl* rfh = nullptr;
-  RenderFrameProxyHost* rfph = RenderFrameProxyHost::FromID(
-      GetProcess()->GetID(), routing_id);
+  RenderFrameProxyHost* rfph = nullptr;
+  LookupRenderFrameHostOrProxy(GetProcess()->GetID(), routing_id, &rfh, &rfph);
   if (rfph) {
     FrameTree* frame_tree = rfph->frame_tree_node()->frame_tree();
     FrameTreeNode* frame_tree_node = frame_tree->FindByRoutingID(
         GetProcess()->GetID(), routing_id);
     rfh = frame_tree_node->render_manager()->current_frame_host();

[Charlie Reis, 2017/05/05 21:03:08]

Seems like we can clean up these 4 lines quite a bit, to:
rfh = rfph->frame_tree_node()->current_frame_host();

dmazzoni@: I'm guessing this just predated those APIs?

[lpz, 2017/05/10 14:21:09]

Done.

-  } else {
-    rfh = RenderFrameHostImpl::FromID(GetProcess()->GetID(), routing_id);
-
-    // As a sanity check, make sure we're within the same frame tree and
-    // crash the renderer if not.
-    if (rfh &&
-        rfh->frame_tree_node()->frame_tree() !=
-            frame_tree_node()->frame_tree()) {
-      AccessibilityFatalError();
-      return ui::AXTreeIDRegistry::kNoAXTreeID;
-    }
   }
 
   if (!rfh)
     return ui::AXTreeIDRegistry::kNoAXTreeID;
 
+  // As a sanity check, make sure we're within the same frame tree and
+  // crash the renderer if not.
+  if (rfh->frame_tree_node()->frame_tree() != frame_tree_node()->frame_tree()) {
+    AccessibilityFatalError();
+    return ui::AXTreeIDRegistry::kNoAXTreeID;
+  }
+
   return rfh->GetAXTreeID();
 }
 
 ui::AXTreeIDRegistry::AXTreeID
 RenderFrameHostImpl::BrowserPluginInstanceIDToAXTreeID(int instance_id) {
   RenderFrameHostImpl* guest = static_cast<RenderFrameHostImpl*>(
       delegate()->GetGuestByInstanceID(this, instance_id));
   if (!guest)
     return ui::AXTreeIDRegistry::kNoAXTreeID;
 
@@ skipping 289 matching lines @@
 }
 
 void RenderFrameHostImpl::ForwardGetInterfaceToRenderFrame(
     const std::string& interface_name,
     mojo::ScopedMessagePipeHandle pipe) {
   GetRemoteInterfaces()->GetInterface(interface_name, std::move(pipe));
 }
 #endif
 
 }  // namespace content