Ensure RemoteViewportIntersection rect persists across frame navigations

content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc

Index: content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc b/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
index 3c04ce9d3ecccaa1d6ac5577194c939ab7e79e4d..d589fd24a098eb977a834671bf9527a60c53c084 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
+++ b/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
@@ -53,6 +53,8 @@ class MockRenderWidgetHostDelegate : public RenderWidgetHostDelegate {
   void SelectAll() override {}
 };
 
+}  // namespace
+
 class MockCrossProcessFrameConnector : public CrossProcessFrameConnector {
  public:
   MockCrossProcessFrameConnector() : CrossProcessFrameConnector(nullptr) {}
@@ -63,6 +65,10 @@ class MockCrossProcessFrameConnector : public CrossProcessFrameConnector {
     last_surface_info_ = surface_info;
   }
 
+  void SetViewportIntersection(const gfx::Rect& intersection) {
+    viewport_intersection_rect_ = intersection;
+  }
+
   RenderWidgetHostViewBase* GetParentRenderWidgetHostView() override {
     return nullptr;
   }
@@ -70,8 +76,6 @@ class MockCrossProcessFrameConnector : public CrossProcessFrameConnector {
   cc::SurfaceInfo last_surface_info_;
 };
 
-}  // namespace
-
 class RenderWidgetHostViewChildFrameTest : public testing::Test {
  public:
   RenderWidgetHostViewChildFrameTest()
@@ -244,4 +248,25 @@ TEST_F(RenderWidgetHostViewChildFrameTest, FrameEviction) {
   EXPECT_TRUE(view_->has_frame());
 }
 
+// Tests that the viewport intersection rect is dispatched to the RenderWidget
+// whenever screen rects are updated.
+TEST_F(RenderWidgetHostViewChildFrameTest, ViewportIntersectionUpdated) {
+  gfx::Rect intersection_rect(5, 5, 100, 80);
+  test_frame_connector_->SetViewportIntersection(intersection_rect);
+
+  MockRenderProcessHost* process =
+      static_cast<MockRenderProcessHost*>(widget_host_->GetProcess());
+  process->Init();
+
+  widget_host_->Init();
+
+  const IPC::Message* intersection_update =
+      process->sink().GetUniqueMessageMatching(
+          ViewMsg_SetViewportIntersection::ID);
+  ASSERT_TRUE(intersection_update);
+  std::tuple<gfx::Rect> sent_rect;
+  ViewMsg_SetViewportIntersection::Read(intersection_update, &sent_rect);
+  EXPECT_EQ(intersection_rect, std::get<0>(sent_rect));
+}
+
 }  // namespace content