scheduler: Implement task observers

content/child/threaded_data_provider.cc

Index: content/child/threaded_data_provider.cc
diff --git a/content/child/threaded_data_provider.cc b/content/child/threaded_data_provider.cc
index 6a533d35f81010a488a34aa92d5436f2a1d23551..64daeebb8e3f8f3bf793450d3081642f9aecf429 100644
--- a/content/child/threaded_data_provider.cc
+++ b/content/child/threaded_data_provider.cc
@@ -108,10 +108,11 @@ void DataProviderMessageFilter::OnReceivedData(int request_id,
                                                int data_length,
                                                int encoded_data_length) {
   DCHECK(io_message_loop_->BelongsToCurrentThread());
-  background_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
-      &ThreadedDataProvider::OnReceivedDataOnBackgroundThread,
-      background_thread_resource_provider_,
-      data_offset, data_length, encoded_data_length));
+  background_thread_.TaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&ThreadedDataProvider::OnReceivedDataOnBackgroundThread,
+                 background_thread_resource_provider_, data_offset, data_length,
+                 encoded_data_length));
 }
 
 }  // anonymous namespace
@@ -186,9 +187,9 @@ void ThreadedDataProvider::Stop() {
     // ThreadedDataProvider gets created.
     DCHECK(current_background_thread ==
         static_cast<WebThreadImpl*>(&background_thread_));
-    background_thread_.message_loop()->PostTask(FROM_HERE,
-        base::Bind(&ThreadedDataProvider::StopOnBackgroundThread,
-                   base::Unretained(this)));
+    background_thread_.TaskRunner()->PostTask(
+        FROM_HERE, base::Bind(&ThreadedDataProvider::StopOnBackgroundThread,
+                              base::Unretained(this)));
   }
 }
 
@@ -213,7 +214,8 @@ void ThreadedDataProvider::OnRequestCompleteForegroundThread(
       const base::TimeTicks& renderer_completion_time) {
   DCHECK(ChildThreadImpl::current());
 
-  background_thread_.message_loop()->PostTask(FROM_HERE,
+  background_thread_.TaskRunner()->PostTask(
+      FROM_HERE,
       base::Bind(&ThreadedDataProvider::OnRequestCompleteBackgroundThread,
                  base::Unretained(this), resource_dispatcher,
                  request_complete_data, renderer_completion_time));
@@ -241,7 +243,8 @@ void ThreadedDataProvider::OnResourceMessageFilterAddedMainThread() {
   // We bounce this message from the I/O thread via the main thread and then
   // to our background thread, following the same path as incoming data before
   // our filter gets added, to make sure there's nothing still incoming.
-  background_thread_.message_loop()->PostTask(FROM_HERE,
+  background_thread_.TaskRunner()->PostTask(
+      FROM_HERE,
       base::Bind(
           &ThreadedDataProvider::OnResourceMessageFilterAddedBackgroundThread,
           background_thread_weak_factory_->GetWeakPtr()));
@@ -295,10 +298,10 @@ void ThreadedDataProvider::OnReceivedDataOnForegroundThread(
     const char* data, int data_length, int encoded_data_length) {
   DCHECK(ChildThreadImpl::current());
 
-  background_thread_.message_loop()->PostTask(FROM_HERE,
-      base::Bind(&ThreadedDataProvider::ForwardAndACKData,
-                 base::Unretained(this),
-                 data, data_length, encoded_data_length));
+  background_thread_.TaskRunner()->PostTask(
+      FROM_HERE, base::Bind(&ThreadedDataProvider::ForwardAndACKData,
+                            base::Unretained(this), data, data_length,
+                            encoded_data_length));
 }
 
 void ThreadedDataProvider::ForwardAndACKData(const char* data,