Cleanup resourceless_software_draw()

content/browser/android/in_process/synchronous_compositor_output_surface.cc

Index: content/browser/android/in_process/synchronous_compositor_output_surface.cc
diff --git a/content/browser/android/in_process/synchronous_compositor_output_surface.cc b/content/browser/android/in_process/synchronous_compositor_output_surface.cc
index 682c530dc3938d61d0557ddb5e439a1998102c00..59556ad894a191dd0bef8f95399947fe3892a0fd 100644
--- a/content/browser/android/in_process/synchronous_compositor_output_surface.cc
+++ b/content/browser/android/in_process/synchronous_compositor_output_surface.cc
@@ -200,9 +200,15 @@ SynchronousCompositorOutputSurface::DemandDrawSw(SkCanvas* canvas) {
   surface_size_ = gfx::Size(canvas->getDeviceSize().width(),
                             canvas->getDeviceSize().height());
 
-  // Resourceless software draw does not need viewport_for_tiling.
-  gfx::Rect empty;
-  InvokeComposite(transform, clip, clip, empty, gfx::Transform(), false);
+  // Pass in the cached hw viewport and transform for tile priority to avoid
+  // tile thrashing when the WebView is alternating between hardware and
+  // software draws.
+  InvokeComposite(transform,
+                  clip,
+                  clip,
+                  cached_hw_viewport_rect_for_tile_priority_,
+                  cached_hw_transform_for_tile_priority_,
+                  false);
 
   return frame_holder_.Pass();
 }