Move the logic to retrieve the WebPluginContainer to LocalFrame and Node.

third_party/WebKit/Source/web/WebInputMethodControllerImpl.cpp

Index: third_party/WebKit/Source/web/WebInputMethodControllerImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebInputMethodControllerImpl.cpp b/third_party/WebKit/Source/web/WebInputMethodControllerImpl.cpp
index b1ed72e6131dbd161b54a432dfae687ec0b34b55..4904552fb870447ae6fb16914b96736c7bc2ed4f 100644
--- a/third_party/WebKit/Source/web/WebInputMethodControllerImpl.cpp
+++ b/third_party/WebKit/Source/web/WebInputMethodControllerImpl.cpp
@@ -158,10 +158,11 @@ InputMethodController& WebInputMethodControllerImpl::GetInputMethodController()
 
 WebPlugin* WebInputMethodControllerImpl::FocusedPluginIfInputMethodSupported()
     const {
-  WebPluginContainerBase* container =
-      WebLocalFrameImpl::CurrentPluginContainer(GetFrame());
-  if (container && container->SupportsInputMethod())
-    return container->Plugin();
+  if (GetFrame()) {

[dcheng, 2017/05/19 09:07:02]

This GetFrame() check shouldn't be required.

We probably need to clean up some of the ownership here: it's confusing because
this object is owned by a unique_ptr on WebLocalFrameImpl, and this object has a
weak member back to the WebLocalFrame. So despite the WeakMember<> here, they
have the same lifetime.

The only time this will return null is if we are calling public API methods on
|this| after the frame is already detached--but by definition, the embedder
already called Close(), so it would violate the API contract to do so.

[slangley, 2017/05/21 23:53:33]

Removed the check - no other methods have it.

+    WebPluginContainerBase* container = GetFrame()->GetWebPluginContainerBase();
+    if (container && container->SupportsInputMethod())
+      return container->Plugin();
+  }
   return nullptr;
 }