Move compositor InputHandler from RenderViewImpl to RenderWidget.

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index 031199d6675b7907a7f77c7e2eb8dc81a63a6c7d..090212a785cd79a2f8e55c1aa873d3d1d45f9022 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -1323,13 +1323,18 @@ void FrameLoader::commitProvisionalLoad() {
     return;
 
   if (isLoadingMainFrame()) {
+    // TODO(wjmaclean): Instead of passing |m_frame| here we pass nullptr
+    // instead so the properties will be set on the WebView. We do this since,
+    // while we are loading, the WebFrameWidget for m_frame may not yet
+    // be available.

[dcheng, 2016/11/04 21:00:02]

Can we switch the order of initialization in CreateMainFrame so this case can't
happen?

[wjmaclean, 2016/11/07 15:57:27]

It's possible we can switch the order, though I don't know for sure yet. If we
*do* switch the order, might it be safe to try that in a follow-on CL, one that
is a bit smaller and easier to reason about?

[dcheng, 2016/11/08 18:11:00]

Can we investigate doing this cleanup preemptively? We've been trying to
rationalize when things can be null in Blink: as you've experienced, it's far
too arbitrary at the moment. =)

[wjmaclean, 2016/11/09 18:09:38]

Actually, as I recall, this only seems to have been an issue in unit tests. I
checked this out further, and in those tests, the frameWidget is *never* created
it seems, so it's not something we need to change (other than handling the null
pointer case). I added a check in ChromeClientImpl that includes a LOG message
(I'm open to more useful wording for that message if you have any suggestions).

     m_frame->page()->chromeClient().setEventListenerProperties(
-        WebEventListenerClass::TouchStartOrMove,
+        nullptr, WebEventListenerClass::TouchStartOrMove,
         WebEventListenerProperties::Nothing);
     m_frame->page()->chromeClient().setEventListenerProperties(
-        WebEventListenerClass::MouseWheel, WebEventListenerProperties::Nothing);
+        nullptr, WebEventListenerClass::MouseWheel,
+        WebEventListenerProperties::Nothing);
     m_frame->page()->chromeClient().setEventListenerProperties(
-        WebEventListenerClass::TouchEndOrCancel,
+        nullptr, WebEventListenerClass::TouchEndOrCancel,
         WebEventListenerProperties::Nothing);
   }