[Experimental, WIP] Demo version of extracting WebView selection data from CompositorFrame.

content/browser/frame_host/render_widget_host_view_guest.cc

Index: content/browser/frame_host/render_widget_host_view_guest.cc
diff --git a/content/browser/frame_host/render_widget_host_view_guest.cc b/content/browser/frame_host/render_widget_host_view_guest.cc
index dee512201fa42dd20f15dd2f97cd8ecf79e9a6ac..5a52e0d6f9bd98065db5dbbae4c6e8f1b8e648fb 100644
--- a/content/browser/frame_host/render_widget_host_view_guest.cc
+++ b/content/browser/frame_host/render_widget_host_view_guest.cc
@@ -6,6 +6,7 @@
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
+#include "cc/output/viewport_selection_bound.h"
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_factory.h"
 #include "cc/surfaces/surface_manager.h"
@@ -221,6 +222,24 @@ void RenderWidgetHostViewGuest::OnSwapCompositorFrame(
     return;
   }
 
+  DCHECK(platform_view_);
+  // Only forward our selection information if (1) we have focus, and (2) our
+  // focused node isn't a plugin (which might be a nested browser plugin, in
+  // which case its RenderWidgetHoseViewGuest will forward the selection
+  // information).
+  if (guest_->focused() && !platform_view_->focused_node_is_plugin()) {
+    cc::ViewportSelectionBound start = frame->metadata.selection.start;
+    gfx::PointF edge_top = guest_->GetScreenCoordinates(start.edge_top);
+    gfx::PointF edge_bottom = guest_->GetScreenCoordinates(start.edge_bottom);
+    fprintf(stderr, "wjm: RWHVG::OnSwapCompositorFrame(%p) Screen "
+            "edge_top=(%6.1f,%6.1f) edge_bottom=(%6.1f,%6.1f)\n",
+            this, edge_top.x(), edge_top.y(), edge_bottom.x(), edge_bottom.y());
+    fprintf(stderr, "wjm: RWHVG::OnSwapCompositorFrame(%p) Window "
+            "edge_top=(%6.1f,%6.1f) edge_bottom=(%6.1f,%6.1f)\n",
+            this, start.edge_top.x(), start.edge_top.y(),
+            start.edge_bottom.x(), start.edge_bottom.y());
+  }
+
   cc::RenderPass* root_pass =
       frame->delegated_frame_data->render_pass_list.back();