Adding Navigation Throttles to DevTools

content/browser/devtools/render_frame_devtools_agent_host.cc

Index: content/browser/devtools/render_frame_devtools_agent_host.cc
diff --git a/content/browser/devtools/render_frame_devtools_agent_host.cc b/content/browser/devtools/render_frame_devtools_agent_host.cc
index 6646dcdbf47c312cb9b59f53c6a4341c49b66388..46edcdec42bda32396174b2dc68d487e0536031d 100644
--- a/content/browser/devtools/render_frame_devtools_agent_host.cc
+++ b/content/browser/devtools/render_frame_devtools_agent_host.cc
@@ -13,6 +13,7 @@
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/devtools/devtools_frame_trace_recorder.h"
 #include "content/browser/devtools/devtools_protocol_handler.h"
+#include "content/browser/devtools/page_navigation_throttle.h"
 #include "content/browser/devtools/protocol/browser_handler.h"
 #include "content/browser/devtools/protocol/dom_handler.h"
 #include "content/browser/devtools/protocol/emulation_handler.h"
@@ -345,6 +346,20 @@ void RenderFrameDevToolsAgentHost::OnBeforeNavigation(
     agent_host->AboutToNavigate(navigation_handle);
 }
 
+// static
+std::unique_ptr<NavigationThrottle>
+RenderFrameDevToolsAgentHost::GetThrottleForNavigation(
+    NavigationHandle* navigation_handle) {
+  FrameTreeNode* frame_tree_node =
+      static_cast<NavigationHandleImpl*>(navigation_handle)->frame_tree_node();
+  RenderFrameDevToolsAgentHost* agent_host = FindAgentHost(frame_tree_node);

[dgozman, 2016/07/07 19:25:58]

Do you want to throttle navigations in subframes as well?

[alex clarke (OOO till 29th), 2016/07/08 10:37:58]

Yes we do :)  Is it better to go via the WebContents?

[dgozman, 2016/07/08 19:19:59]

OOPIFs step in here: we should go up the tree to the local root. See how it's
done here (but you'll have to use frame tree nodes I think):
DevToolsAgentHost::GetOrCreateFor(RenderFrameHost* frame_host)

[alex clarke (OOO till 29th), 2016/07/08 20:55:37]

I'm not up to speed with these trees but it looks like it's possible to get the
frame host and use the same logic from
DevToolsAgentHost::GetOrCreateFor(RenderFrameHost* frame_host).

+  if (agent_host) {
+    return agent_host->page_handler_->GetThrottleForNavigation(
+        navigation_handle);
+  }
+  return nullptr;
+}
+
 RenderFrameDevToolsAgentHost::RenderFrameDevToolsAgentHost(
     RenderFrameHostImpl* host)
     : browser_handler_(new devtools::browser::BrowserHandler()),