cc: Clear the invalidation history when moving between compositors.

cc/resources/picture_pile.cc

Index: cc/resources/picture_pile.cc
diff --git a/cc/resources/picture_pile.cc b/cc/resources/picture_pile.cc
index 2b15aeadb7c9ada7fee2003e0d0c465fd7a91785..04e08010073bfff27c10447f0bf5273ae9de2f47 100644
--- a/cc/resources/picture_pile.cc
+++ b/cc/resources/picture_pile.cc
@@ -214,6 +214,11 @@ bool PicturePile::UpdateAndExpandInvalidation(
   return true;
 }
 
+void PicturePile::DidMoveToNewCompositor() {
+  for (auto& map_pair : picture_map_)
+    map_pair.second.ResetInvalidationHistory();
+}
+
 bool PicturePile::ApplyInvalidationAndResize(const gfx::Rect& interest_rect,
                                              Region* invalidation,
                                              const gfx::Size& layer_size,
@@ -747,6 +752,11 @@ bool PicturePile::PictureInfo::NeedsRecording(int frame_number,
           (GetInvalidationFrequency() < kInvalidationFrequencyThreshold));
 }
 
+void PicturePile::PictureInfo::ResetInvalidationHistory() {
+  invalidation_history_.reset();
+  last_frame_number_ = 0;
+}
+
 void PicturePile::SetBufferPixels(int new_buffer_pixels) {
   if (new_buffer_pixels == buffer_pixels())
     return;