Add a NavigationThrottle to the public content/ interface

This CL adds a NavigationThrottle class to the public content/ interface. A NavigationThrottle is used to control the flow of navigations. It lives entirely on the UI thread. Eventually, all components that want the functionality of a ResourceThrottle for navigations should transition to a NavigationThrottle: the new architecture for navigations (browser-side navigation) will not support ResourceThrottles for main resources load. See https://docs.google.com/document/d/1ICLLQoC9EsZ-bWH4ZKRhPCIoZKn6pOj02SlGl6SKH6Y/edit?pli=1#heading=h.fmxjmgvbgg7x for the design doc.

This Cl also transition the InterceptNavigationresourceThrottle to the Navigationthrottle model.
BUG=504347

Review URL: https://codereview.chromium.org/1269813002

Cr-Commit-Position: refs/heads/master@{#350092}

3 files changed, 21 insertions, 8 deletions

diff --git a/android_webview/browser/aw_content_browser_client.cc b/android_webview/browser/aw_content_browser_client.cc
index 759c844..ab14d49 100644
--- a/android_webview/browser/aw_content_browser_client.cc
+++ b/android_webview/browser/aw_content_browser_client.cc
@@ -25,10 +25,13 @@
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "components/cdm/browser/cdm_message_filter_android.h"
+#include "components/navigation_interception/intercept_navigation_delegate.h"
 #include "content/public/browser/access_token_store.h"
 #include "content/public/browser/browser_message_filter.h"
 #include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/client_certificate_delegate.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/navigation_throttle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
@@ -487,6 +490,22 @@ void AwContentBrowserClient::OverrideWebkitPrefs(
       content::WebContents::FromRenderViewHost(rvh), web_prefs);
 }
 
+ScopedVector<content::NavigationThrottle>
+AwContentBrowserClient::CreateThrottlesForNavigation(
+    content::NavigationHandle* navigation_handle) {
+  ScopedVector<content::NavigationThrottle> throttles;
+  if (navigation_handle->IsInMainFrame() ||
+      (!navigation_handle->GetURL().SchemeIs(url::kHttpScheme) &&
+       !navigation_handle->GetURL().SchemeIs(url::kHttpsScheme) &&
+       !navigation_handle->GetURL().SchemeIs(url::kAboutScheme))) {
+    throttles.push_back(
+        navigation_interception::InterceptNavigationDelegate::CreateThrottleFor(
+            navigation_handle)
+            .Pass());
+  }
+  return throttles.Pass();
+}
+
 #if defined(VIDEO_HOLE)
 content::ExternalVideoSurfaceContainer*
 AwContentBrowserClient::OverrideCreateExternalVideoSurfaceContainer(
diff --git a/android_webview/browser/aw_content_browser_client.h b/android_webview/browser/aw_content_browser_client.h
index d811cf2..a3a814e 100644
--- a/android_webview/browser/aw_content_browser_client.h
+++ b/android_webview/browser/aw_content_browser_client.h
@@ -142,6 +142,8 @@ class AwContentBrowserClient : public content::ContentBrowserClient {
       std::map<int, base::MemoryMappedFile::Region>* regions) override;
   void OverrideWebkitPrefs(content::RenderViewHost* rvh,
                            content::WebPreferences* web_prefs) override;
+  ScopedVector<content::NavigationThrottle> CreateThrottlesForNavigation(
+      content::NavigationHandle* navigation_handle) override;
 #if defined(VIDEO_HOLE)
   content::ExternalVideoSurfaceContainer*
   OverrideCreateExternalVideoSurfaceContainer(
diff --git a/android_webview/browser/renderer_host/aw_resource_dispatcher_host_delegate.cc b/android_webview/browser/renderer_host/aw_resource_dispatcher_host_delegate.cc
index 1d9e585..ed7c52b 100644
--- a/android_webview/browser/renderer_host/aw_resource_dispatcher_host_delegate.cc
+++ b/android_webview/browser/renderer_host/aw_resource_dispatcher_host_delegate.cc
@@ -221,14 +221,6 @@ void AwResourceDispatcherHostDelegate::RequestBeginning(
   throttles->push_back(new IoThreadClientThrottle(
       request_info->GetChildID(), request_info->GetRenderFrameID(), request));
 
-  if (resource_type == content::RESOURCE_TYPE_MAIN_FRAME ||
-      (resource_type == content::RESOURCE_TYPE_SUB_FRAME &&
-       !request->url().SchemeIs(url::kHttpScheme) &&
-       !request->url().SchemeIs(url::kHttpsScheme) &&
-       !request->url().SchemeIs(url::kAboutScheme))) {
-    throttles->push_back(InterceptNavigationDelegate::CreateThrottleFor(
-        request));
-  }
   if (resource_type != content::RESOURCE_TYPE_MAIN_FRAME)
     InterceptNavigationDelegate::UpdateUserGestureCarryoverInfo(request);
 }