Polymer: Remove unused paper-dropdown-menu, paper-menu-button.

third_party/polymer/v1_0/bower.json

Index: third_party/polymer/v1_0/bower.json
diff --git a/third_party/polymer/v1_0/bower.json b/third_party/polymer/v1_0/bower.json
index 6f6c80a8a7ee435240133004cb173cf845611076..1e6d06ae11e5ccc0e3a22bbf84791920b228d377 100644
--- a/third_party/polymer/v1_0/bower.json
+++ b/third_party/polymer/v1_0/bower.json
@@ -39,7 +39,6 @@
     "paper-dialog-behavior": "PolymerElements/paper-dialog-behavior#1.2.7",
     "paper-dialog": "PolymerElements/paper-dialog#1.1.0",
     "paper-drawer-panel": "PolymerElements/paper-drawer-panel#1.0.10",
-    "paper-dropdown-menu": "PolymerElements/paper-dropdown-menu#1.4.1",
     "paper-fab": "PolymerElements/paper-fab#1.2.0",
     "paper-header-panel": "PolymerElements/paper-header-panel#1.1.6",
     "paper-icon-button": "PolymerElements/paper-icon-button#1.1.6",
@@ -47,7 +46,6 @@
     "paper-item": "PolymerElements/paper-item#1.2.1",
     "paper-listbox": "PolymerelEments/paper-listbox#1.1.2",
     "paper-material": "PolymerElements/paper-material#1.0.6",
-    "paper-menu-button": "PolymerElements/paper-menu-button#1.5.2",
     "paper-menu": "PolymerElements/paper-menu#1.3.0",
     "paper-progress": "PolymerElements/paper-progress#1.0.10",
     "paper-radio-button": "PolymerElements/paper-radio-button#1.4.0",