Revert of Teach navigation throttles how to cancel requests in WillProcessResponse. (patchset #6 id:100001 of https://codereview.chromium.org/1616943003/ )

Reason for revert:
Windows tree doesn't like me: https://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20%28dbg%29%281%29/builds/45328/steps/browser_tests/logs/stdio

Original issue's description:
> Teach navigation throttles how to cancel requests in WillProcessResponse.
>
> This is the first step towards moving various response-time checks up
> from Blink into the browser. To support things like 'X-Frame-Options',
> we'll need to do throttle checks after we can evaluate headers. This
> patch starts us down that path by teaching NavigationHandleImpl,
> NavigationResourceThrottle, and NavigationThrottle about response-time
> checks. This patch shouldn't introduce any behavioral changes, as no
> NavigationThrottle actually uses the new functionality yet.
>
> BUG=555418
> CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_site_isolation
>
> Committed: https://crrev.com/409b51d438ea3f99d37025372adaf4d730553857
> Cr-Commit-Position: refs/heads/master@{#372332}

TBR=clamy@chromium.org,davidben@chromium.org,mmenke@chromium.org,nasko@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=555418

Review URL: https://codereview.chromium.org/1645363002

Cr-Commit-Position: refs/heads/master@{#372350}

6 files changed, 13 insertions, 279 deletions

diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index 2716893..a8d32e9 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -147,23 +147,14 @@ bool NavigationHandleImpl::IsErrorPage() {
 }
 
 void NavigationHandleImpl::Resume() {
-  if (state_ != DEFERRING_START && state_ != DEFERRING_REDIRECT &&
-      state_ != DEFERRING_RESPONSE) {
+  if (state_ != DEFERRING_START && state_ != DEFERRING_REDIRECT)
     return;
-  }
 
   NavigationThrottle::ThrottleCheckResult result = NavigationThrottle::DEFER;
   if (state_ == DEFERRING_START) {
     result = CheckWillStartRequest();
-  } else if (state_ == DEFERRING_REDIRECT) {
-    result = CheckWillRedirectRequest();
   } else {
-    result = CheckWillProcessResponse();
-
-    // If the navigation is about to proceed after processing the response, then
-    // it's ready to commit.
-    if (result == NavigationThrottle::PROCEED)
-      ReadyToCommitNavigation(render_frame_host_, response_headers_);
+    result = CheckWillRedirectRequest();
   }
 
   if (result != NavigationThrottle::DEFER)
@@ -288,28 +279,6 @@ void NavigationHandleImpl::WillRedirectRequest(
     RunCompleteCallback(result);
 }
 
-void NavigationHandleImpl::WillProcessResponse(
-    RenderFrameHostImpl* render_frame_host,
-    scoped_refptr<net::HttpResponseHeaders> response_headers,
-    const ThrottleChecksFinishedCallback& callback) {
-  DCHECK(!render_frame_host_ || render_frame_host_ == render_frame_host);
-  render_frame_host_ = render_frame_host;
-  response_headers_ = response_headers;
-  state_ = WILL_PROCESS_RESPONSE;
-  complete_callback_ = callback;
-
-  // Notify each throttle of the response.
-  NavigationThrottle::ThrottleCheckResult result = CheckWillProcessResponse();
-
-  // If the navigation is about to proceed, then it's ready to commit.
-  if (result == NavigationThrottle::PROCEED)
-    ReadyToCommitNavigation(render_frame_host, response_headers);
-
-  // If the navigation is not deferred, run the callback.
-  if (result != NavigationThrottle::DEFER)
-    RunCompleteCallback(result);
-}
-
 void NavigationHandleImpl::DidRedirectNavigation(const GURL& new_url) {
   url_ = new_url;
   GetDelegate()->DidRedirectNavigation(this);
@@ -400,46 +369,13 @@ NavigationHandleImpl::CheckWillRedirectRequest() {
   return NavigationThrottle::PROCEED;
 }
 
-NavigationThrottle::ThrottleCheckResult
-NavigationHandleImpl::CheckWillProcessResponse() {
-  DCHECK(state_ == WILL_PROCESS_RESPONSE || state_ == DEFERRING_RESPONSE);
-  DCHECK(state_ != WILL_PROCESS_RESPONSE || next_index_ == 0);
-  DCHECK(state_ != DEFERRING_RESPONSE || next_index_ != 0);
-  for (size_t i = next_index_; i < throttles_.size(); ++i) {
-    NavigationThrottle::ThrottleCheckResult result =
-        throttles_[i]->WillProcessResponse();
-    switch (result) {
-      case NavigationThrottle::PROCEED:
-        continue;
-
-      case NavigationThrottle::CANCEL:
-      case NavigationThrottle::CANCEL_AND_IGNORE:
-        state_ = CANCELING;
-        return result;
-
-      case NavigationThrottle::DEFER:
-        state_ = DEFERRING_RESPONSE;
-        next_index_ = i + 1;
-        return result;
-    }
-  }
-  next_index_ = 0;
-  state_ = WILL_PROCESS_RESPONSE;
-  return NavigationThrottle::PROCEED;
-}
-
 void NavigationHandleImpl::RunCompleteCallback(
     NavigationThrottle::ThrottleCheckResult result) {
   DCHECK(result != NavigationThrottle::DEFER);
+  if (!complete_callback_.is_null())
+    complete_callback_.Run(result);
 
-  ThrottleChecksFinishedCallback callback = complete_callback_;
   complete_callback_.Reset();
-
-  if (!callback.is_null())
-    callback.Run(result);
-
-  // No code after running the callback, as it might have resulted in our
-  // destruction.
 }
 
 }  // namespace content
diff --git a/content/browser/frame_host/navigation_handle_impl.h b/content/browser/frame_host/navigation_handle_impl.h
index 626465f..192cdab 100644
--- a/content/browser/frame_host/navigation_handle_impl.h
+++ b/content/browser/frame_host/navigation_handle_impl.h
@@ -160,18 +160,6 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
       scoped_refptr<net::HttpResponseHeaders> response_headers,
       const ThrottleChecksFinishedCallback& callback);
 
-  // Called when the URLRequest has delivered response headers and metadata.
-  // |callback| will be called when all throttle checks have completed,
-  // allowing the caller to cancel the navigation or let it proceed.
-  // NavigationHandle will not call |callback| with a result of DEFER.
-  // If the result is PROCEED, then 'ReadyToCommitNavigation' will be called
-  // with |render_frame_host| and |response_headers| just before calling
-  // |callback|.
-  void WillProcessResponse(
-      RenderFrameHostImpl* render_frame_host,
-      scoped_refptr<net::HttpResponseHeaders> response_headers,
-      const ThrottleChecksFinishedCallback& callback);
-
   // Returns the FrameTreeNode this navigation is happening in.
   FrameTreeNode* frame_tree_node() { return frame_tree_node_; }
 
@@ -202,8 +190,6 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
     WILL_REDIRECT_REQUEST,
     DEFERRING_REDIRECT,
     CANCELING,
-    WILL_PROCESS_RESPONSE,
-    DEFERRING_RESPONSE,
     READY_TO_COMMIT,
     DID_COMMIT,
     DID_COMMIT_ERROR_PAGE,
@@ -215,7 +201,6 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
 
   NavigationThrottle::ThrottleCheckResult CheckWillStartRequest();
   NavigationThrottle::ThrottleCheckResult CheckWillRedirectRequest();
-  NavigationThrottle::ThrottleCheckResult CheckWillProcessResponse();
 
   // Helper function to run and reset the |complete_callback_|. This marks the
   // end of a round of NavigationThrottleChecks.
diff --git a/content/browser/frame_host/navigation_handle_impl_unittest.cc b/content/browser/frame_host/navigation_handle_impl_unittest.cc
index 950ee99..ee999cb 100644
--- a/content/browser/frame_host/navigation_handle_impl_unittest.cc
+++ b/content/browser/frame_host/navigation_handle_impl_unittest.cc
@@ -9,10 +9,9 @@
 
 namespace content {
 
-// Test version of a NavigationThrottle. It will always return the current
+// Test version of a NavigationThrottle. It will always return the same
 // NavigationThrottle::ThrottleCheckResult |result_|, It also monitors the
-// number of times WillStartRequest, WillRedirectRequest, and
-// WillProcessResponse were called.
+// number of times WillStartRequest and WillRedirectRequest were called.
 class TestNavigationThrottle : public NavigationThrottle {
  public:
   TestNavigationThrottle(NavigationHandle* handle,
@@ -20,8 +19,7 @@ class TestNavigationThrottle : public NavigationThrottle {
       : NavigationThrottle(handle),
         result_(result),
         will_start_calls_(0),
-        will_redirect_calls_(0),
-        will_process_response_calls_(0) {}
+        will_redirect_calls_(0) {}
 
   ~TestNavigationThrottle() override {}
 
@@ -35,25 +33,16 @@ class TestNavigationThrottle : public NavigationThrottle {
     return result_;
   }
 
-  NavigationThrottle::ThrottleCheckResult WillProcessResponse() override {
-    ++will_process_response_calls_;
-    return result_;
-  }
-
   int will_start_calls() const { return will_start_calls_; }
   int will_redirect_calls() const { return will_redirect_calls_; }
-  int will_process_response_calls() const {
-    return will_process_response_calls_;
-  }
 
  private:
   // The result returned by the TestNavigationThrottle.
   NavigationThrottle::ThrottleCheckResult result_;
 
-  // The number of times each handler was called.
+  // The number of times WillStartRequest and WillRedirectRequest were called.
   int will_start_calls_;
   int will_redirect_calls_;
-  int will_process_response_calls_;
 };
 
 class NavigationHandleImplTest : public RenderViewHostImplTestHarness {
@@ -83,10 +72,6 @@ class NavigationHandleImplTest : public RenderViewHostImplTestHarness {
     return test_handle_->state() == NavigationHandleImpl::DEFERRING_REDIRECT;
   }
 
-  bool IsDeferringResponse() {
-    return test_handle_->state() == NavigationHandleImpl::DEFERRING_RESPONSE;
-  }
-
   bool IsCanceling() {
     return test_handle_->state() == NavigationHandleImpl::CANCELING;
   }
@@ -123,24 +108,6 @@ class NavigationHandleImplTest : public RenderViewHostImplTestHarness {
                    base::Unretained(this)));
   }
 
-  // Helper function to call WillProcessResponse on |handle|. If this function
-  // returns DEFER, |callback_result_| will be set to the actual result of the
-  // throttle checks when they are finished.
-  // TODO(clamy): this should also simulate that WillStartRequest was called if
-  // it has not been called before.
-  void SimulateWillProcessResponse() {
-    was_callback_called_ = false;
-    callback_result_ = NavigationThrottle::DEFER;
-
-    // It's safe to use base::Unretained since the NavigationHandle is owned by
-    // the NavigationHandleImplTest.
-    test_handle_->WillProcessResponse(
-        main_test_rfh(),
-        scoped_refptr<net::HttpResponseHeaders>(),
-        base::Bind(&NavigationHandleImplTest::UpdateThrottleCheckResult,
-                   base::Unretained(this)));
-  }
-
   // Returns the handle used in tests.
   NavigationHandleImpl* test_handle() const { return test_handle_.get(); }
 
@@ -183,80 +150,46 @@ TEST_F(NavigationHandleImplTest, ResumeDeferred) {
       CreateTestNavigationThrottle(NavigationThrottle::DEFER);
   EXPECT_FALSE(IsDeferringStart());
   EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_FALSE(IsDeferringResponse());
   EXPECT_EQ(0, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Simulate WillStartRequest. The request should be deferred. The callback
   // should not have been called.
   SimulateWillStartRequest();
   EXPECT_TRUE(IsDeferringStart());
   EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_FALSE(IsDeferringResponse());
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Resume the request. It should no longer be deferred and the callback
   // should have been called.
   test_handle()->Resume();
   EXPECT_FALSE(IsDeferringStart());
   EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_FALSE(IsDeferringResponse());
   EXPECT_TRUE(was_callback_called());
   EXPECT_EQ(NavigationThrottle::PROCEED, callback_result());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Simulate WillRedirectRequest. The request should be deferred. The callback
   // should not have been called.
   SimulateWillRedirectRequest();
   EXPECT_FALSE(IsDeferringStart());
   EXPECT_TRUE(IsDeferringRedirect());
-  EXPECT_FALSE(IsDeferringResponse());
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(1, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Resume the request. It should no longer be deferred and the callback
   // should have been called.
   test_handle()->Resume();
   EXPECT_FALSE(IsDeferringStart());
   EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_FALSE(IsDeferringResponse());
   EXPECT_TRUE(was_callback_called());
   EXPECT_EQ(NavigationThrottle::PROCEED, callback_result());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(1, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
-
-  // Simulate WillProcessResponse. It will be deferred. The callback should not
-  // have been called.
-  SimulateWillProcessResponse();
-  EXPECT_FALSE(IsDeferringStart());
-  EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_TRUE(IsDeferringResponse());
-  EXPECT_FALSE(was_callback_called());
-  EXPECT_EQ(1, test_throttle->will_start_calls());
-  EXPECT_EQ(1, test_throttle->will_redirect_calls());
-  EXPECT_EQ(1, test_throttle->will_process_response_calls());
-
-  // Resume the request. It should no longer be deferred and the callback should
-  // have been called.
-  test_handle()->Resume();
-  EXPECT_FALSE(IsDeferringStart());
-  EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_FALSE(IsDeferringResponse());
-  EXPECT_TRUE(was_callback_called());
-  EXPECT_EQ(NavigationThrottle::PROCEED, callback_result());
-  EXPECT_EQ(1, test_throttle->will_start_calls());
-  EXPECT_EQ(1, test_throttle->will_redirect_calls());
-  EXPECT_EQ(1, test_throttle->will_process_response_calls());
-  EXPECT_TRUE(test_handle()->GetRenderFrameHost());
 }
 
 // Checks that a navigation deferred during WillStartRequest can be properly
@@ -268,7 +201,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredWillStart) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Simulate WillStartRequest. The request should be deferred. The callback
   // should not have been called.
@@ -278,7 +210,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredWillStart) {
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Cancel the request. The callback should have been called.
   test_handle()->CancelDeferredNavigation(
@@ -290,7 +221,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredWillStart) {
   EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 }
 
 // Checks that a navigation deferred during WillRedirectRequest can be properly
@@ -302,7 +232,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredWillRedirect) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Simulate WillRedirectRequest. The request should be deferred. The callback
   // should not have been called.
@@ -312,7 +241,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredWillRedirect) {
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(0, test_throttle->will_start_calls());
   EXPECT_EQ(1, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Cancel the request. The callback should have been called.
   test_handle()->CancelDeferredNavigation(
@@ -324,7 +252,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredWillRedirect) {
   EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
   EXPECT_EQ(0, test_throttle->will_start_calls());
   EXPECT_EQ(1, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 }
 
 // Checks that a navigation deferred can be canceled and not ignored.
@@ -335,7 +262,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredNoIgnore) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Simulate WillRedirectRequest. The request should be deferred. The callback
   // should not have been called.
@@ -345,7 +271,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredNoIgnore) {
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 
   // Cancel the request. The callback should have been called with CANCEL, and
   // not CANCEL_AND_IGNORE.
@@ -357,7 +282,6 @@ TEST_F(NavigationHandleImplTest, CancelDeferredNoIgnore) {
   EXPECT_EQ(NavigationThrottle::CANCEL, callback_result());
   EXPECT_EQ(1, test_throttle->will_start_calls());
   EXPECT_EQ(0, test_throttle->will_redirect_calls());
-  EXPECT_EQ(0, test_throttle->will_process_response_calls());
 }
 
 // Checks that a NavigationThrottle asking to defer followed by a
@@ -371,10 +295,8 @@ TEST_F(NavigationHandleImplTest, DeferThenProceed) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, defer_throttle->will_start_calls());
   EXPECT_EQ(0, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(0, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
-  EXPECT_EQ(0, proceed_throttle->will_process_response_calls());
 
   // Simulate WillStartRequest. The request should be deferred. The callback
   // should not have been called. The second throttle should not have been
@@ -385,7 +307,6 @@ TEST_F(NavigationHandleImplTest, DeferThenProceed) {
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(1, defer_throttle->will_start_calls());
   EXPECT_EQ(0, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(0, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
 
@@ -398,7 +319,6 @@ TEST_F(NavigationHandleImplTest, DeferThenProceed) {
   EXPECT_EQ(NavigationThrottle::PROCEED, callback_result());
   EXPECT_EQ(1, defer_throttle->will_start_calls());
   EXPECT_EQ(0, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(1, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
 
@@ -411,7 +331,6 @@ TEST_F(NavigationHandleImplTest, DeferThenProceed) {
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(1, defer_throttle->will_start_calls());
   EXPECT_EQ(1, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(1, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
 
@@ -424,7 +343,6 @@ TEST_F(NavigationHandleImplTest, DeferThenProceed) {
   EXPECT_EQ(NavigationThrottle::PROCEED, callback_result());
   EXPECT_EQ(1, defer_throttle->will_start_calls());
   EXPECT_EQ(1, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(1, proceed_throttle->will_start_calls());
   EXPECT_EQ(1, proceed_throttle->will_redirect_calls());
 }
@@ -440,7 +358,6 @@ TEST_F(NavigationHandleImplTest, DeferThenCancelWillStartRequest) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, defer_throttle->will_start_calls());
   EXPECT_EQ(0, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
 
@@ -453,7 +370,6 @@ TEST_F(NavigationHandleImplTest, DeferThenCancelWillStartRequest) {
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(1, defer_throttle->will_start_calls());
   EXPECT_EQ(0, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
 
@@ -467,7 +383,6 @@ TEST_F(NavigationHandleImplTest, DeferThenCancelWillStartRequest) {
   EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
   EXPECT_EQ(1, defer_throttle->will_start_calls());
   EXPECT_EQ(0, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(1, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
 }
@@ -483,7 +398,6 @@ TEST_F(NavigationHandleImplTest, DeferThenCancelWillRedirectRequest) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, defer_throttle->will_start_calls());
   EXPECT_EQ(0, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
 
@@ -496,7 +410,6 @@ TEST_F(NavigationHandleImplTest, DeferThenCancelWillRedirectRequest) {
   EXPECT_FALSE(was_callback_called());
   EXPECT_EQ(0, defer_throttle->will_start_calls());
   EXPECT_EQ(1, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
 
@@ -510,7 +423,6 @@ TEST_F(NavigationHandleImplTest, DeferThenCancelWillRedirectRequest) {
   EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
   EXPECT_EQ(0, defer_throttle->will_start_calls());
   EXPECT_EQ(1, defer_throttle->will_redirect_calls());
-  EXPECT_EQ(0, defer_throttle->will_process_response_calls());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(1, cancel_throttle->will_redirect_calls());
 }
@@ -528,7 +440,6 @@ TEST_F(NavigationHandleImplTest, CancelThenProceedWillStartRequest) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(0, cancel_throttle->will_process_response_calls());
   EXPECT_EQ(0, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
 
@@ -542,7 +453,6 @@ TEST_F(NavigationHandleImplTest, CancelThenProceedWillStartRequest) {
   EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
   EXPECT_EQ(1, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(0, cancel_throttle->will_process_response_calls());
   EXPECT_EQ(0, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
 }
@@ -560,7 +470,6 @@ TEST_F(NavigationHandleImplTest, CancelThenProceedWillRedirectRequest) {
   EXPECT_FALSE(IsDeferringRedirect());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(0, cancel_throttle->will_process_response_calls());
   EXPECT_EQ(0, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
 
@@ -574,74 +483,8 @@ TEST_F(NavigationHandleImplTest, CancelThenProceedWillRedirectRequest) {
   EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
   EXPECT_EQ(0, cancel_throttle->will_start_calls());
   EXPECT_EQ(1, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(0, cancel_throttle->will_process_response_calls());
-  EXPECT_EQ(0, proceed_throttle->will_start_calls());
-  EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
-}
-
-// Checks that a NavigationThrottle asking to proceed followed by a
-// NavigationThrottle asking to cancel behave correctly in WillProcessResponse.
-// Both throttles will be called, and the request will be cancelled.
-TEST_F(NavigationHandleImplTest, ProceedThenCancelWillProcessResponse) {
-  TestNavigationThrottle* proceed_throttle =
-      CreateTestNavigationThrottle(NavigationThrottle::PROCEED);
-  TestNavigationThrottle* cancel_throttle =
-      CreateTestNavigationThrottle(NavigationThrottle::CANCEL_AND_IGNORE);
-  EXPECT_FALSE(IsDeferringStart());
-  EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_EQ(0, cancel_throttle->will_start_calls());
-  EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(0, cancel_throttle->will_process_response_calls());
-  EXPECT_EQ(0, proceed_throttle->will_start_calls());
-  EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
-  EXPECT_EQ(0, proceed_throttle->will_process_response_calls());
-
-  // Simulate WillRedirectRequest. The request should not be deferred. The
-  // callback should have been called.
-  SimulateWillProcessResponse();
-  EXPECT_FALSE(IsDeferringStart());
-  EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_TRUE(was_callback_called());
-  EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
-  EXPECT_EQ(0, cancel_throttle->will_start_calls());
-  EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(1, cancel_throttle->will_process_response_calls());
-  EXPECT_EQ(0, proceed_throttle->will_start_calls());
-  EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
-  EXPECT_EQ(1, proceed_throttle->will_process_response_calls());
-}
-
-// Checks that a NavigationThrottle asking to cancel followed by a
-// NavigationThrottle asking to proceed behave correctly in WillProcessResponse.
-// The navigation will be canceled directly, and the second throttle will not
-// be called.
-TEST_F(NavigationHandleImplTest, CancelThenProceedWillProcessResponse) {
-  TestNavigationThrottle* cancel_throttle =
-      CreateTestNavigationThrottle(NavigationThrottle::CANCEL_AND_IGNORE);
-  TestNavigationThrottle* proceed_throttle =
-      CreateTestNavigationThrottle(NavigationThrottle::PROCEED);
-  EXPECT_FALSE(IsDeferringStart());
-  EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_EQ(0, cancel_throttle->will_start_calls());
-  EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(0, cancel_throttle->will_process_response_calls());
-  EXPECT_EQ(0, proceed_throttle->will_start_calls());
-  EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
-
-  // Simulate WillRedirectRequest. The request should not be deferred. The
-  // callback should have been called. The second throttle should not have
-  // been notified.
-  SimulateWillProcessResponse();
-  EXPECT_FALSE(IsDeferringStart());
-  EXPECT_FALSE(IsDeferringRedirect());
-  EXPECT_TRUE(was_callback_called());
-  EXPECT_EQ(NavigationThrottle::CANCEL_AND_IGNORE, callback_result());
-  EXPECT_EQ(0, cancel_throttle->will_start_calls());
-  EXPECT_EQ(0, cancel_throttle->will_redirect_calls());
-  EXPECT_EQ(1, cancel_throttle->will_process_response_calls());
   EXPECT_EQ(0, proceed_throttle->will_start_calls());
   EXPECT_EQ(0, proceed_throttle->will_redirect_calls());
-  EXPECT_EQ(0, proceed_throttle->will_process_response_calls());
 }
 
 }  // namespace content
diff --git a/content/browser/loader/navigation_resource_throttle.cc b/content/browser/loader/navigation_resource_throttle.cc
index 6321062..44fd0c1 100644
--- a/content/browser/loader/navigation_resource_throttle.cc
+++ b/content/browser/loader/navigation_resource_throttle.cc
@@ -4,13 +4,9 @@
 
 #include "content/browser/loader/navigation_resource_throttle.h"
 
-#include "base/bind.h"
 #include "base/callback.h"
-#include "base/location.h"
-#include "base/logging.h"
 #include "content/browser/frame_host/navigation_handle_impl.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
-#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/resource_controller.h"
 #include "content/public/browser/resource_request_info.h"
@@ -30,7 +26,7 @@ typedef base::Callback<void(NavigationThrottle::ThrottleCheckResult)>
 void SendCheckResultToIOThread(UIChecksPerformedCallback callback,
                                NavigationThrottle::ThrottleCheckResult result) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  DCHECK_NE(result, NavigationThrottle::DEFER);
+  CHECK(result != NavigationThrottle::DEFER);
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
                           base::Bind(callback, result));
 }
@@ -97,28 +93,21 @@ void CheckWillRedirectRequestOnUIThread(
 }
 
 void WillProcessResponseOnUIThread(
-    UIChecksPerformedCallback callback,
     int render_process_id,
     int render_frame_host_id,
     scoped_refptr<net::HttpResponseHeaders> headers) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   RenderFrameHostImpl* render_frame_host =
       RenderFrameHostImpl::FromID(render_process_id, render_frame_host_id);
-  if (!render_frame_host) {
-    SendCheckResultToIOThread(callback, NavigationThrottle::PROCEED);
+  if (!render_frame_host)
     return;
-  }
 
   NavigationHandleImpl* navigation_handle =
       render_frame_host->navigation_handle();
-  if (!navigation_handle) {
-    SendCheckResultToIOThread(callback, NavigationThrottle::PROCEED);
+  if (!navigation_handle)
     return;
-  }
 
-  navigation_handle->WillProcessResponse(
-      render_frame_host, headers,
-      base::Bind(&SendCheckResultToIOThread, callback));
+  navigation_handle->ReadyToCommitNavigation(render_frame_host, headers);
 }
 
 }  // namespace
@@ -215,15 +204,10 @@ void NavigationResourceThrottle::WillProcessResponse(bool* defer) {
         request_->response_headers()->raw_headers());
   }
 
-  UIChecksPerformedCallback callback =
-      base::Bind(&NavigationResourceThrottle::OnUIChecksPerformed,
-                 weak_ptr_factory_.GetWeakPtr());
-
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
-      base::Bind(&WillProcessResponseOnUIThread, callback, render_process_id,
+      base::Bind(&WillProcessResponseOnUIThread, render_process_id,
                  render_frame_id, response_headers));
-  *defer = true;
 }
 
 const char* NavigationResourceThrottle::GetNameForLogging() const {
diff --git a/content/public/browser/navigation_throttle.cc b/content/public/browser/navigation_throttle.cc
index 5c795d6..ac3b3aa 100644
--- a/content/public/browser/navigation_throttle.cc
+++ b/content/public/browser/navigation_throttle.cc
@@ -20,9 +20,4 @@ NavigationThrottle::WillRedirectRequest() {
   return NavigationThrottle::PROCEED;
 }
 
-NavigationThrottle::ThrottleCheckResult
-NavigationThrottle::WillProcessResponse() {
-  return NavigationThrottle::PROCEED;
-}
-
 }  // namespace content
diff --git a/content/public/browser/navigation_throttle.h b/content/public/browser/navigation_throttle.h
index 5876343..fff64b1 100644
--- a/content/public/browser/navigation_throttle.h
+++ b/content/public/browser/navigation_throttle.h
@@ -55,15 +55,6 @@ class CONTENT_EXPORT NavigationThrottle {
   // CANCEL_AND_IGNORE or DEFER and perform the destruction asynchronously.
   virtual ThrottleCheckResult WillRedirectRequest();
 
-  // Called when a response's headers and metadata are available.
-  //
-  // The implementer is responsible for ensuring that the WebContents this
-  // throttle is associated with remain alive during the duration of this
-  // method. Failing to do so will result in use-after-free bugs. Should the
-  // implementer need to destroy the WebContents, it should return CANCEL,
-  // CANCEL_AND_IGNORE and perform the destruction asynchronously.
-  virtual ThrottleCheckResult WillProcessResponse();
-
   // The NavigationHandle that is tracking the information related to this
   // navigation.
   NavigationHandle* navigation_handle() const { return navigation_handle_; }