Fix the problem that notifications and panels overlap.

chrome/browser/notifications/balloon_collection_gtk.cc

Index: chrome/browser/notifications/balloon_collection_gtk.cc
diff --git a/chrome/browser/notifications/balloon_collection_gtk.cc b/chrome/browser/notifications/balloon_collection_gtk.cc
index 2420735f72016bcb90b005615545ae8ed5203de6..c6453e98f9137e260a604ddef629e8a5e31f16b7 100644
--- a/chrome/browser/notifications/balloon_collection_gtk.cc
+++ b/chrome/browser/notifications/balloon_collection_gtk.cc
@@ -35,6 +35,39 @@ int BalloonCollectionImpl::Layout::VerticalEdgeMargin() const {
   return 5;
 }
 
+gfx::Point BalloonCollectionImpl::Layout::GetLayoutOrigin() const {
+  int x = 0;
+  int y = 0;
+  switch (placement_) {
+    case VERTICALLY_FROM_TOP_LEFT:
+      x = work_area_.x() + HorizontalEdgeMargin();
+      y = work_area_.y() + VerticalEdgeMargin();
+      break;
+    case VERTICALLY_FROM_TOP_RIGHT:
+      x = work_area_.right() - HorizontalEdgeMargin();
+      y = work_area_.y() + VerticalEdgeMargin();
+      break;
+    case VERTICALLY_FROM_BOTTOM_LEFT:
+      x = work_area_.x() + HorizontalEdgeMargin();
+      // For this placement, balloon needs to stay on top of left-most panels
+      // to avoid overlapping.
+      y = work_area_.bottom() - VerticalEdgeMargin() -
+          bottom_left_offset_to_move_above_panels_;
+      break;
+    case VERTICALLY_FROM_BOTTOM_RIGHT:
+      x = work_area_.right() - HorizontalEdgeMargin();
+      // For this placement, balloon needs to stay on top of right-most panels
+      // to avoid overlapping.
+      y = work_area_.bottom() - VerticalEdgeMargin() -
+          bottom_right_offset_to_move_above_panels_;
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+  return gfx::Point(x, y);
+}
+
 void BalloonCollectionImpl::PositionBalloons(bool reposition) {
   PositionBalloonsInternal(reposition);
 }