Added AddDownload communication path and observers

content/browser/background_fetch/background_fetch_client_proxy.cc

Index: content/browser/background_fetch/background_fetch_client_proxy.cc
diff --git a/content/browser/background_fetch/background_fetch_client_proxy.cc b/content/browser/background_fetch/background_fetch_client_proxy.cc
index d1dd0316d0a5ae19990435925806c1da42781e04..8f53efbd9e1828b7fb277e81df66ab69dfec25cb 100644
--- a/content/browser/background_fetch/background_fetch_client_proxy.cc
+++ b/content/browser/background_fetch/background_fetch_client_proxy.cc
@@ -6,18 +6,44 @@
 
 #include "content/browser/background_fetch/background_fetch_context.h"
 #include "content/browser/background_fetch/background_fetch_registration_id.h"
+#include "content/common/background_fetch/background_fetch_types.h"
+#include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 BackgroundFetchClientProxy::BackgroundFetchClientProxy(
+    BrowserContext* browser_context,
     BackgroundFetchContext* background_fetch_context)
-    : background_fetch_context_(background_fetch_context) {
+    : background_fetch_context_(background_fetch_context),
+      weak_ptr_factory_(this) {
   DCHECK(background_fetch_context);
+  DCHECK(browser_context);
+  background_fetch_client_ = browser_context->GetBackgroundFetchClient();
+  DCHECK(background_fetch_client_);
 }
 
 BackgroundFetchClientProxy::~BackgroundFetchClientProxy() = default;
 
+void BackgroundFetchClientProxy::AddDownload(
+    const GURL& url,
+    const std::string& registration_id,
+    const BackgroundFetchOptions& options) {
+  BrowserThread::PostTask(

[Peter Beverloo, 2017/04/24 14:39:15]

DCHECK_CURRENTLY_ON() to both new methods.

AddDownload() is called on the IO thread, and BackgroundFetchClient::AddDownload
needs to be called on the UI thread.

+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&BackgroundFetchClientProxy::AddDownloadOnIO,
+                 weak_ptr_factory_.GetWeakPtr(), url, registration_id,
+                 options));
+}
+
+void BackgroundFetchClientProxy::AddDownloadOnIO(
+    const GURL& url,
+    const std::string& registration_id,
+    const BackgroundFetchOptions& options) {
+  background_fetch_client_->AddDownload(url, registration_id, options.title,
+                                        options.total_download_size);
+}
+
 void BackgroundFetchClientProxy::CleanupAllTasks() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,