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..b78c7ba41bfbccb52b3ac6d9f987e71c00692773 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 +346,24 @@ 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();
+  RenderFrameHost* frame_host = frame_tree_node->current_frame_host();

[dgozman, 2016/07/09 01:57:00]

Could there be no current frame host? Let's instead walk up the frame tree
nodes? I'm not an expert in RFHs and FTNs though.

[alex clarke (OOO till 29th), 2016/07/11 09:25:19]

Done.

+  while (frame_host && !ShouldCreateDevToolsFor(frame_host))
+    frame_host = frame_host->GetParent();
+  DCHECK(frame_host);
+  RenderFrameDevToolsAgentHost* agent_host = FindAgentHost(frame_host);
+  if (agent_host && agent_host->page_handler_) {
+    return agent_host->page_handler_->GetThrottleForNavigation(
+        navigation_handle);
+  }
+  return nullptr;
+}
+
 RenderFrameDevToolsAgentHost::RenderFrameDevToolsAgentHost(
     RenderFrameHostImpl* host)
     : browser_handler_(new devtools::browser::BrowserHandler()),