Send compositor frame IPC with metadata.

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
diff --git a/cc/layer_tree_host_impl.cc b/cc/layer_tree_host_impl.cc
index b558568b008981c4a7a897bf10ff5bd45b55708f..a004cbcfadf1dfa6e814f711ca3e21928be4d00e 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -9,6 +9,7 @@
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
 #include "cc/append_quads_data.h"
+#include "cc/compositor_frame_metadata.h"
 #include "cc/damage_tracker.h"
 #include "cc/debug_rect_history.h"
 #include "cc/delay_based_time_source.h"
@@ -699,6 +700,23 @@ void LayerTreeHostImpl::onVSyncParametersChanged(double monotonicTimebase, doubl
     m_client->onVSyncParametersChanged(timebase, interval);
 }
 
+CompositorFrameMetadata LayerTreeHostImpl::makeCompositorFrameMetadata() const
+{
+    CompositorFrameMetadata metadata;
+    metadata.rootScrollOffset = m_rootScrollLayerImpl->scrollOffset() + m_rootScrollLayerImpl->scrollDelta() + m_pinchZoomViewport.scrollDelta();
+    metadata.pageScaleFactor = m_pinchZoomViewport.totalPageScaleFactor();
+    metadata.viewportSize = m_pinchZoomViewport.bounds().size();
+    metadata.rootLayerSize = m_rootScrollLayerImpl->bounds();
+    metadata.minPageScaleFactor = m_pinchZoomViewport.minPageScaleFactor();
+    metadata.maxPageScaleFactor = m_pinchZoomViewport.maxPageScaleFactor();
+    if (!m_settings.pageScalePinchZoomEnabled) {
+        metadata.rootScrollOffset.Scale(1 / m_pinchZoomViewport.pageScaleFactor());
+        metadata.rootLayerSize.Scale(1 / m_pinchZoomViewport.pageScaleFactor());
+    }
+
+    return metadata;
+}
+
 void LayerTreeHostImpl::drawLayers(const FrameData& frame)
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::drawLayers");