Revert "Remove navigation start observing from DataUseAscriber"

This reverts commit 73722a14.

Reason for revert: Breaking the Linux x64 build
https://ci.chromium.org/buildbot/chromium/Linux%20x64/55031

Original change's description:
> Remove navigation start observing from DataUseAscriber
> 
> There's no reason to PostTask a bunch of data to the IO thread to do a
> no-op method.
> 
> This CL should change no behavior.
> 
> Bug: 792524
> Change-Id: Ia0f88da99c72fa3369b164a2fd25352f77d13544
> Reviewed-on: https://chromium-review.googlesource.com/827980
> Reviewed-by: rajendrant <rajendrant@chromium.org>
> Commit-Queue: rajendrant <rajendrant@chromium.org>
> Commit-Queue: Charlie Harrison <csharrison@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#524424}

TBR=csharrison@chromium.org,rajendrant@chromium.org

Change-Id: I00a16f8e2ee77b767f4289ad01ca4a05c711fdc9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 792524
Reviewed-on: https://chromium-review.googlesource.com/830473Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524431}

chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc

@@ -299,6 +299,14 @@ void ChromeDataUseAscriber::RenderFrameDeleted(int render_process_id,
   subframe_to_mainframe_map_.erase(key);
 }
 
+void ChromeDataUseAscriber::DidStartMainFrameNavigation(
+    const GURL& gurl,
+    int render_process_id,
+    int render_frame_id,
+    void* navigation_handle) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+}
+
 void ChromeDataUseAscriber::ReadyToCommitMainFrameNavigation(
     content::GlobalRequestID global_request_id,
     int render_process_id,

chrome/browser/data_use_measurement/chrome_data_use_ascriber.h

@@ -79,6 +79,12 @@ class ChromeDataUseAscriber : public DataUseAscriber {
                           int main_render_process_id,
                           int main_render_frame_id);
 
+  // Called when a main frame navigation is started.
+  void DidStartMainFrameNavigation(const GURL& gurl,
+                                   int render_process_id,
+                                   int render_frame_id,
+                                   void* navigation_handle);
+
   // Called when a main frame navigation is ready to be committed in a
   // renderer.
   void ReadyToCommitMainFrameNavigation(

chrome/browser/data_use_measurement/chrome_data_use_ascriber_service.cc

@@ -123,6 +123,24 @@ void ChromeDataUseAscriberService::RenderFrameDeleted(
                      main_render_frame_id));
 }
 
+void ChromeDataUseAscriberService::DidStartNavigation(
+    content::NavigationHandle* navigation_handle) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  if (!navigation_handle->IsInMainFrame())
+    return;
+
+  if (!ascriber_)
+    return;
+  content::WebContents* web_contents = navigation_handle->GetWebContents();
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::BindOnce(&ChromeDataUseAscriber::DidStartMainFrameNavigation,
+                     base::Unretained(ascriber_), navigation_handle->GetURL(),
+                     web_contents->GetMainFrame()->GetProcess()->GetID(),
+                     web_contents->GetMainFrame()->GetRoutingID(),
+                     navigation_handle));
+}
+
 void ChromeDataUseAscriberService::ReadyToCommitNavigation(
     content::NavigationHandle* navigation_handle) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

chrome/browser/data_use_measurement/chrome_data_use_ascriber_service.h

@@ -45,6 +45,11 @@ class ChromeDataUseAscriberService : public KeyedService {
   // are propagated.
   void RenderFrameDeleted(content::RenderFrameHost* render_frame_host);
 
+  // Called when a navigation is started. Propagates main frame navigation
+  // start to the |ascriber_| on the IO thread. NavigationHandle methods
+  // cannot be called on the IO thread, so the pointer is cast to void*.
+  void DidStartNavigation(content::NavigationHandle* navigation_handle);
+
   // Called when the navigation is ready to be committed in a renderer.
   // Propagates the event to the |ascriber_| on the IO thread. NavigationHandle
   // methods cannot be called on the IO thread, so the pointer is cast to void*.

chrome/browser/data_use_measurement/chrome_data_use_ascriber_unittest.cc

@@ -220,7 +220,11 @@ TEST_F(ChromeDataUseAscriberTest, MainFrameNavigation) {
   ascriber()->OnBeforeUrlRequest(request.get());
   EXPECT_EQ(2u, recorders().size());
 
-  // Navigation commits.
+  // Navigation starts.
+  ascriber()->DidStartMainFrameNavigation(GURL("http://test.com"),
+                                          kRenderProcessId, kRenderFrameId,
+                                          kNavigationHandle);
+
   ascriber()->ReadyToCommitMainFrameNavigation(
       content::GlobalRequestID(kRenderProcessId, 0), kRenderProcessId,
       kRenderFrameId);
@@ -258,6 +262,9 @@ TEST_F(ChromeDataUseAscriberTest, SubResourceRequestsAttributed) {
   ascriber()->OnBeforeUrlRequest(page_load_a_main_frame_request.get());
 
   // Commit the page load.
+  ascriber()->DidStartMainFrameNavigation(GURL("http://test.com"),
+                                          kRenderProcessId, kRenderFrameId,
+                                          kNavigationHandle);
   ascriber()->ReadyToCommitMainFrameNavigation(
       content::GlobalRequestID(kRenderProcessId, 0), kRenderProcessId,
       kRenderFrameId);
@@ -276,6 +283,9 @@ TEST_F(ChromeDataUseAscriberTest, SubResourceRequestsAttributed) {
   ascriber()->OnBeforeUrlRequest(page_load_b_main_frame_request.get());
 
   // Commit the second page load.
+  ascriber()->DidStartMainFrameNavigation(GURL("http://test_2.com"),
+                                          kRenderProcessId, kRenderFrameId,
+                                          kNavigationHandle);
   ascriber()->ReadyToCommitMainFrameNavigation(
       content::GlobalRequestID(kRenderProcessId, 0), kRenderProcessId,
       kRenderFrameId);
@@ -323,6 +333,9 @@ TEST_F(ChromeDataUseAscriberTest, SubResourceRequestsAfterNavigationFinish) {
   // First page load 'a'.
   ascriber()->RenderFrameCreated(kRenderProcessId, kRenderFrameId, -1, -1);
   ascriber()->OnBeforeUrlRequest(page_load_a_mainresource.get());
+  ascriber()->DidStartMainFrameNavigation(GURL("http://test.com"),
+                                          kRenderProcessId, kRenderFrameId,
+                                          kNavigationHandle);
   ascriber()->ReadyToCommitMainFrameNavigation(
       content::GlobalRequestID(kRenderProcessId, 0), kRenderProcessId,
       kRenderFrameId);
@@ -353,6 +366,9 @@ TEST_F(ChromeDataUseAscriberTest, SubResourceRequestsAfterNavigationFinish) {
 
   // Second page load 'b' on the same main render frame.
   ascriber()->OnBeforeUrlRequest(page_load_b_mainresource.get());
+  ascriber()->DidStartMainFrameNavigation(GURL("http://test_2.com"),
+                                          kRenderProcessId, kRenderFrameId,
+                                          kNavigationHandle);
   ascriber()->ReadyToCommitMainFrameNavigation(
       content::GlobalRequestID(kRenderProcessId, 0), kRenderProcessId,
       kRenderFrameId);
@@ -390,6 +406,9 @@ TEST_F(ChromeDataUseAscriberTest, SubResourceRequestsAfterNavigationFinish) {
   // Third page load 'c' on the same main render frame with
   // same_document_navigation set.
   ascriber()->OnBeforeUrlRequest(page_load_c_mainresource.get());
+  ascriber()->DidStartMainFrameNavigation(GURL("http://test_c.com"),
+                                          kRenderProcessId, kRenderFrameId,
+                                          kNavigationHandle);
   ascriber()->ReadyToCommitMainFrameNavigation(
       content::GlobalRequestID(kRenderProcessId, 0), kRenderProcessId,
       kRenderFrameId);
@@ -450,7 +469,11 @@ TEST_F(ChromeDataUseAscriberTest, PageLoadObserverNotified) {
 
   ascriber()->OnBeforeUrlRequest(request.get());
 
-  // Navigation starts and is ready to commit.
+  // Navigation starts.
+  ascriber()->DidStartMainFrameNavigation(GURL("http://test.com"),
+                                          kRenderProcessId, kRenderFrameId,
+                                          kNavigationHandle);
+
   ascriber()->ReadyToCommitMainFrameNavigation(
       content::GlobalRequestID(kRenderProcessId, 0), kRenderProcessId,
       kRenderFrameId);

chrome/browser/data_use_measurement/data_use_web_contents_observer.cc

@@ -64,6 +64,11 @@ void DataUseWebContentsObserver::RenderFrameDeleted(
   service_->RenderFrameDeleted(render_frame_host);
 }
 
+void DataUseWebContentsObserver::DidStartNavigation(
+    content::NavigationHandle* navigation_handle) {
+  service_->DidStartNavigation(navigation_handle);
+}
+
 void DataUseWebContentsObserver::ReadyToCommitNavigation(
     content::NavigationHandle* navigation_handle) {
   service_->ReadyToCommitNavigation(navigation_handle);

chrome/browser/data_use_measurement/data_use_web_contents_observer.h

@@ -35,6 +35,8 @@ class DataUseWebContentsObserver
   // WebContentsObserver implementation:
   void RenderFrameCreated(content::RenderFrameHost* render_frame_host) override;
   void RenderFrameDeleted(content::RenderFrameHost* render_frame_host) override;
+  void DidStartNavigation(
+      content::NavigationHandle* navigation_handle) override;
   void ReadyToCommitNavigation(
       content::NavigationHandle* navigation_handle) override;
   void WasShown() override;