[Offline Pages] Allow BackgroundLoader to track network bytes using prerenderer hook-in.

chrome/browser/android/offline_pages/background_loader_offliner.cc

Index: chrome/browser/android/offline_pages/background_loader_offliner.cc
diff --git a/chrome/browser/android/offline_pages/background_loader_offliner.cc b/chrome/browser/android/offline_pages/background_loader_offliner.cc
index 07b32f956610f7021e66e5f8d32a9027f553c854..a4028a123db774c4bd48c86585d4ec32b4e1af60 100644
--- a/chrome/browser/android/offline_pages/background_loader_offliner.cc
+++ b/chrome/browser/android/offline_pages/background_loader_offliner.cc
@@ -11,6 +11,7 @@
 #include "chrome/browser/profiles/profile.h"
 #include "components/offline_pages/core/background/save_page_request.h"
 #include "components/offline_pages/core/client_namespace_constants.h"
+#include "components/offline_pages/core/downloads/download_ui_adapter.h"
 #include "components/offline_pages/core/offline_page_model.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/navigation_handle.h"
@@ -19,9 +20,11 @@
 namespace offline_pages {
 
 namespace {
-long kOfflinePageDelayMs = 2000;
+const long kOfflinePageDelayMs = 2000;
 }  // namespace
 
+BackgroundLoaderOffliner* BackgroundLoaderOffliner::offliner_ = nullptr;
+
 BackgroundLoaderOffliner::BackgroundLoaderOffliner(
     content::BrowserContext* browser_context,
     const OfflinerPolicy* policy,
@@ -32,14 +35,23 @@ BackgroundLoaderOffliner::BackgroundLoaderOffliner(
       save_state_(NONE),
       page_load_state_(SUCCESS),
       page_delay_ms_(kOfflinePageDelayMs),
+      network_bytes_(0LL),
       weak_ptr_factory_(this) {
   DCHECK(offline_page_model_);
   DCHECK(browser_context_);
+  offliner_ = this;
 }
 
 BackgroundLoaderOffliner::~BackgroundLoaderOffliner() {}
 
-// TODO(dimich): Invoke progress_callback as appropriate.
+// static
+BackgroundLoaderOffliner* BackgroundLoaderOffliner::FromWebContents(
+    content::WebContents* contents) {

[dewittj, 2017/03/09 22:33:17]

It might be better to get it this way:
auto context = contents->GetBrowserContext();
auto request_coordinator = RCFactory::GetForBrowserContext(context);
auto offliner = request_coordinator->GetOffliner()

Then you don't have dangling static pointers to worry about.

+  if (offliner_ && offliner_->web_contents() == contents)
+    return offliner_;
+  return nullptr;
+}
+
 bool BackgroundLoaderOffliner::LoadAndSave(
     const SavePageRequest& request,
     const CompletionCallback& completion_callback,
@@ -109,6 +121,7 @@ bool BackgroundLoaderOffliner::LoadAndSave(
   // Track copy of pending request.
   pending_request_.reset(new SavePageRequest(request));
   completion_callback_ = completion_callback;
+  progress_callback_ = progress_callback;
 
   // Listen for app foreground/background change.
   app_listener_.reset(new base::android::ApplicationStatusListener(
@@ -250,6 +263,14 @@ void BackgroundLoaderOffliner::SetPageDelayForTest(long delay_ms) {
   page_delay_ms_ = delay_ms;
 }
 
+void BackgroundLoaderOffliner::OnNetworkBytesChanged(int64_t bytes) {
+  if (pending_request_ && save_state_ != SAVING) {
+    network_bytes_ += bytes;
+    SavePageRequest request(*pending_request_.get());
+    progress_callback_.Run(request, network_bytes_);
+  }
+}
+
 void BackgroundLoaderOffliner::SavePage() {
   if (!pending_request_.get()) {
     DVLOG(1) << "Pending request was cleared during delay.";
@@ -334,6 +355,7 @@ void BackgroundLoaderOffliner::OnPageSaved(SavePageResult save_result,
 void BackgroundLoaderOffliner::ResetState() {
   pending_request_.reset();
   page_load_state_ = SUCCESS;
+  network_bytes_ = 0LL;
   // TODO(chili): Remove after RequestCoordinator can handle multiple offliners.
   // We reset the loader and observer after completion so loaders
   // will not be re-used across different requests/tries. This is a temporary