Fix leak reported by valgrind in VideoDestinationHandlerTest.PutFrame

This fix a problem in the unittest where the test ends before all pending cleanup tasks have
completed.

Revert "[MemSheriff] Suppress content_unittests leaks and uninits"
This reverts commit 8ea251ca.

BUG=422087

Review URL: https://codereview.chromium.org/649513003

Cr-Commit-Position: refs/heads/master@{#299123}

content/renderer/media/webrtc/video_destination_handler_unittest.cc

@@ -97,6 +97,13 @@ TEST_F(VideoDestinationHandlerTest, PutFrame) {
         RunClosure(quit_closure));
     frame_writer.Run(image.get(), 10);
     run_loop.Run();
+    // Run all pending tasks to let the the test clean up before the test ends.
+    // This is due to that
+    // FrameWriterDelegate::FrameWriterDelegate::DeliverFrame use
+    // PostTaskAndReply to the IO thread and expects the reply to process
+    // on the main render thread to clean up its resources. However, the
+    // QuitClosure above ends before that.
+    base::MessageLoop::current()->RunUntilIdle();
   }
   EXPECT_EQ(1, sink.number_of_frames());
   native_track->RemoveSink(&sink);

tools/valgrind/memcheck/suppressions.txt

@@ -3469,19 +3469,3 @@
    fun:_ZN5blink13InlineFlowBox5paintERNS_9PaintInfoERKNS_11LayoutPointENS_10LayoutUnitES6_
    fun:_ZN5blink13RootInlineBox5paintERNS_9PaintInfoERKNS_11LayoutPointENS_10LayoutUnitES6_
 }
-{
-   bug_422087a
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN4base8internal20PostTaskAndReplyImpl16PostTaskAndReplyERKN15tracked_objects8LocationERKNS_8CallbackIFvvEEESA_
-   fun:_ZN4base10TaskRunner16PostTaskAndReplyERKN15tracked_objects8LocationERKNS_8CallbackIFvvEEES9_
-   fun:_ZN7content13PpFrameWriter19FrameWriterDelegate12DeliverFrameERK13scoped_*
-}
-{
-   bug_422087b
-   Memcheck:Leak
-   fun:_Znw*
-   ...
-   fun:_ZNSt4listI13scoped_refptrIN5media10VideoFrameEESaIS3_EE9push_backERKS3_
-   fun:_ZN5media14VideoFramePool8PoolImpl13FrameReleasedERK13scoped_refptrINS_10VideoFrameEE
-}