Pepper and WebKit API change to support a plugin knowing if a scrollbar is an overlay one.

webkit/plugins/ppapi/ppapi_plugin_instance.cc

Index: webkit/plugins/ppapi/ppapi_plugin_instance.cc
===================================================================
--- webkit/plugins/ppapi/ppapi_plugin_instance.cc	(revision 95420)
+++ webkit/plugins/ppapi/ppapi_plugin_instance.cc	(working copy)
@@ -61,6 +61,7 @@
 #include "webkit/plugins/ppapi/ppb_graphics_3d_impl.h"
 #include "webkit/plugins/ppapi/ppb_image_data_impl.h"
 #include "webkit/plugins/ppapi/ppb_input_event_impl.h"
+#include "webkit/plugins/ppapi/ppb_scrollbar_group_impl.h"
 #include "webkit/plugins/ppapi/ppb_surface_3d_impl.h"
 #include "webkit/plugins/ppapi/ppb_url_loader_impl.h"
 #include "webkit/plugins/ppapi/ppb_url_request_info_impl.h"
@@ -235,7 +236,8 @@
       message_channel_(NULL),
       sad_plugin_(NULL),
       input_event_mask_(0),
-      filtered_input_event_mask_(0) {
+      filtered_input_event_mask_(0),
+      scrollbar_group_(NULL) {
   pp_instance_ = ResourceTracker::Get()->AddInstance(this);
 
   memset(&current_print_settings_, 0, sizeof(current_print_settings_));
@@ -441,6 +443,16 @@
   // Keep a reference on the stack. See NOTE above.
   scoped_refptr<PluginInstance> ref(this);
 
+  if (scrollbar_group_) {
+    if (event.type == WebInputEvent::MouseEnter) {
+      scrollbar_group_->MouseEnteredContentArea();
+    } else if (event.type == WebInputEvent::MouseMove) {
+      scrollbar_group_->MouseMovedInContentArea();
+    } else if (event.type == WebInputEvent::MouseLeave) {
+      scrollbar_group_->MouseExitedContentArea();
+    }
+  }
+
   bool rv = false;
   if (LoadInputEventInterface()) {
     PP_InputEvent_Class event_class = ClassifyInputEvent(event.type);
@@ -520,6 +532,9 @@
     clip_ = clip;
   }
 
+  if (scrollbar_group_)
+    scrollbar_group_->ContentResized();
+
   PP_Rect pp_position, pp_clip;
   RectToPPRect(position_, &pp_position);
   RectToPPRect(clip_, &pp_clip);
@@ -672,6 +687,16 @@
   plugin_find_interface_->StopFind(pp_instance());
 }
 
+void PluginInstance::WillStartLiveResize() {
+  if (scrollbar_group_)
+    scrollbar_group_->WillStartLiveResize();
+}
+
+void PluginInstance::WillEndLiveResize() {
+  if (scrollbar_group_)
+    scrollbar_group_->WillEndLiveResize();
+}
+
 bool PluginInstance::LoadFindInterface() {
   if (!plugin_find_interface_) {
     plugin_find_interface_ =
@@ -1332,6 +1357,17 @@
   return frame->view()->mainFrame()->document().isPluginDocument();
 }
 
+void PluginInstance::SetScrollbarGroup(
+    PPB_ScrollbarGroup_Impl* scrollbar_group) {
+  if (!IsFullPagePlugin())
+    return;
+
+  // Only handle one scrollbar group for now, i.e. the normal case of one group
+  // for a full-page plugin.
+  DCHECK(!scrollbar_group || !scrollbar_group_);
+  scrollbar_group_ = scrollbar_group;
+}
+
 PPB_Instance_FunctionAPI* PluginInstance::AsPPB_Instance_FunctionAPI() {
   return this;
 }