Remove needs_repainting from the WasShown IPC to the RenderWidget.

This bool is always true, and is not used. No need to send it.
Also removes the dead needs_repainting_on_restore_ from the
RenderWidgetHostImpl.

R=ajwong@chromium.org, dcheng@chromium.org, piman@chromium.org

Bug: 419087
Change-Id: I673e5de215a9118b061478260d0dc012ae078d37
Reviewed-on: https://chromium-review.googlesource.com/1246942Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Albert J. Wong <ajwong@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594482}

content/browser/renderer_host/render_widget_host_impl.cc

@@ -346,7 +346,6 @@ RenderWidgetHostImpl::RenderWidgetHostImpl(RenderWidgetHostDelegate* delegate,
       visual_properties_ack_pending_(false),
       auto_resize_enabled_(false),
       waiting_for_screen_rects_ack_(false),
-      needs_repainting_on_restore_(false),
       is_unresponsive_(false),
       in_flight_event_count_(0),
       in_get_backing_store_(false),
@@ -727,12 +726,9 @@ void RenderWidgetHostImpl::WasShown(bool record_presentation_time) {
   SendScreenRects();
   RestartInputEventAckTimeoutIfNecessary();
 
-  // Always repaint on restore.
-  bool needs_repainting = true;
-  needs_repainting_on_restore_ = false;
-  Send(new ViewMsg_WasShown(
-      routing_id_, needs_repainting,
-      record_presentation_time ? base::TimeTicks::Now() : base::TimeTicks()));
+  Send(new ViewMsg_WasShown(routing_id_, record_presentation_time
+                                             ? base::TimeTicks::Now()
+                                             : base::TimeTicks()));
 
   process_->UpdateClientPriority(this);
 

content/browser/renderer_host/render_widget_host_impl.h

@@ -757,7 +757,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl
  private:
   FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostTest,
                            DontPostponeInputEventAckTimeout);
-  FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostTest, HiddenPaint);
+  FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostTest, HideShowMessages);
   FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostTest, RendererExitedNoDrag);
   FRIEND_TEST_ALL_PREFIXES(RenderWidgetHostTest,
                            StopAndStartInputEventAckTimeout);
@@ -987,12 +987,6 @@ class CONTENT_EXPORT RenderWidgetHostImpl
   // The observers watching us.
   base::ObserverList<RenderWidgetHostObserver>::Unchecked observers_;
 
-  // If true, then we should repaint when restoring even if we have a
-  // backingstore.  This flag is set to true if we receive a paint message
-  // while is_hidden_ to true.  Even though we tell the render widget to hide
-  // itself, a paint message could already be in flight at that point.
-  bool needs_repainting_on_restore_;
-
   // This is true if the renderer is currently unresponsive.
   bool is_unresponsive_;
 

content/browser/renderer_host/render_widget_host_unittest.cc

@@ -1203,9 +1203,9 @@ TEST_F(RenderWidgetHostTest, Background) {
 }
 #endif
 
-// Test that we don't paint when we're hidden, but we still send the ACK. Most
-// of the rest of the painting is tested in the GetBackingStore* ones.
-TEST_F(RenderWidgetHostTest, HiddenPaint) {
+// Test that the RenderWidgetHost tells the renderer when it is hidden and
+// shown, and can accept a racey update from the renderer after hiding.
+TEST_F(RenderWidgetHostTest, HideShowMessages) {
   // Hide the widget, it should have sent out a message to the renderer.
   EXPECT_FALSE(host_->is_hidden_);
   host_->WasHidden();
@@ -1224,13 +1224,8 @@ TEST_F(RenderWidgetHostTest, HiddenPaint) {
   host_->WasShown(false /* record_presentation_time */);
   EXPECT_FALSE(host_->is_hidden_);
 
-  // It should have sent out a restored message with a request to paint.
-  const IPC::Message* restored = process_->sink().GetUniqueMessageMatching(
-      ViewMsg_WasShown::ID);
-  ASSERT_TRUE(restored);
-  std::tuple<bool, base::TimeTicks> needs_repaint;
-  ViewMsg_WasShown::Read(restored, &needs_repaint);
-  EXPECT_TRUE(std::get<0>(needs_repaint));
+  // It should have sent out a restored message.
+  EXPECT_TRUE(process_->sink().GetUniqueMessageMatching(ViewMsg_WasShown::ID));
 }
 
 TEST_F(RenderWidgetHostTest, IgnoreKeyEventsHandledByRenderer) {

content/common/view_messages.h

@@ -266,8 +266,7 @@ IPC_MESSAGE_ROUTED0(ViewMsg_WasHidden)
 // render view is expected to respond with a full repaint if needs_repainting
 // is true. If needs_repainting is false, then this message does not trigger a
 // message in response.
-IPC_MESSAGE_ROUTED2(ViewMsg_WasShown,
-                    bool /* needs_repainting */,
+IPC_MESSAGE_ROUTED1(ViewMsg_WasShown,
                     base::TimeTicks /* show_request_timestamp */)
 
 // Tells the renderer to focus the first (last if reverse is true) focusable

content/renderer/render_frame_impl_browsertest.cc

@@ -211,7 +211,7 @@ TEST_F(RenderFrameImplTest, FrameResize) {
 TEST_F(RenderFrameImplTest, FrameWasShown) {
   RenderFrameTestObserver observer(frame());
 
-  ViewMsg_WasShown was_shown_message(0, true, base::TimeTicks());
+  ViewMsg_WasShown was_shown_message(0, base::TimeTicks());
   frame_widget()->OnMessageReceived(was_shown_message);
 
   EXPECT_FALSE(frame_widget()->is_hidden());
@@ -241,7 +241,7 @@ TEST_F(RenderFrameImplTest, LocalChildFrameWasShown) {
 
   RenderFrameTestObserver observer(grandchild);
 
-  ViewMsg_WasShown was_shown_message(0, true, base::TimeTicks());
+  ViewMsg_WasShown was_shown_message(0, base::TimeTicks());
   frame_widget()->OnMessageReceived(was_shown_message);
 
   EXPECT_FALSE(frame_widget()->is_hidden());
@@ -254,7 +254,7 @@ TEST_F(RenderFrameImplTest, FrameWasShownAfterWidgetClose) {
   ViewMsg_Close close_message(0);
   frame_widget()->OnMessageReceived(close_message);
 
-  ViewMsg_WasShown was_shown_message(0, true, base::TimeTicks());
+  ViewMsg_WasShown was_shown_message(0, base::TimeTicks());
   // Test passes if this does not crash.
   RenderWidget* render_widget =
       static_cast<RenderViewImpl*>(view_)->GetWidget();

content/renderer/render_widget.cc

@@ -803,8 +803,7 @@ void RenderWidget::OnWasHidden() {
     observer.WasHidden();
 }
 
-void RenderWidget::OnWasShown(bool needs_repainting,
-                              base::TimeTicks show_request_timestamp) {
+void RenderWidget::OnWasShown(base::TimeTicks show_request_timestamp) {
   TRACE_EVENT0("renderer", "RenderWidget::OnWasShown");
   // During shutdown we can just ignore this message.
   if (!GetWebWidget())
@@ -816,9 +815,6 @@ void RenderWidget::OnWasShown(bool needs_repainting,
   for (auto& observer : render_frames_)
     observer.WasShown();
 
-  if (!needs_repainting)
-    return;
-
   if (layer_tree_view_ && !show_request_timestamp.is_null()) {
     layer_tree_view_->layer_tree_host()->RequestPresentationTimeForNextFrame(
         CreateTabSwitchingTimeRecorder(show_request_timestamp));

content/renderer/render_widget.h

@@ -601,8 +601,7 @@ class CONTENT_EXPORT RenderWidget
   void OnEnableDeviceEmulation(const blink::WebDeviceEmulationParams& params);
   void OnDisableDeviceEmulation();
   void OnWasHidden();
-  void OnWasShown(bool needs_repainting,
-                  base::TimeTicks show_request_timestamp);
+  void OnWasShown(base::TimeTicks show_request_timestamp);
   void OnCreateVideoAck(int32_t video_id);
   void OnUpdateVideoAck(int32_t video_id);
   void OnRequestSetBoundsAck();