[Chromecast] Fix assert failure + add test in SwapWithBounds path

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index 809bbdd130ed1b838241fe0de5511f3029772587..d6df7a97a75cf9feba462404d5ba76c098b1b315 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -2450,6 +2450,9 @@ void GLRenderer::FinishDrawingFrame() {
   if (overdraw_feedback_)
     FlushOverdrawFeedback(swap_buffer_rect_);
 
+  if (use_swap_with_bounds_)
+    swap_content_bounds_ = current_frame()->root_content_bounds;
+
   current_framebuffer_lock_ = nullptr;
 
   gl_->Disable(GL_BLEND);
@@ -2614,7 +2617,7 @@ void GLRenderer::SwapBuffers(std::vector<ui::LatencyInfo> latency_info) {
   output_frame.latency_info = std::move(latency_info);
   output_frame.size = surface_size;
   if (use_swap_with_bounds_) {
-    output_frame.content_bounds = current_frame()->root_content_bounds;
+    output_frame.content_bounds = std::move(swap_content_bounds_);
   } else if (use_partial_swap_) {
     // If supported, we can save significant bandwidth by only swapping the
     // damaged/scissored region (clamped to the viewport).