import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1190469 - Refactor some code to have a general-purpose snap function available in APZC. r=botond (a4e8706df5)
- Bug 1225761 - Clear axis lock in CancelAnimation and EndTouch. r=botond (1436279d0d)
- Bug 1226316. Fixup to only expand displayport when skating with apz. r=kats (51c49a8fca)
- Bug 1181703 - Allow re-entering the panning state if a second finger is tapped while panning with one finger. r=botond (e87cd85058)
- Bug 1181703 - Add a gtest for making sure a pan can be continued after a second finger does a tap. r=botond (16354bec40)
- Bug 1190469 - Request scroll snapping in a few places that animations are cancelled so that we don't leave things unsnapped. r=botond (4b0ba5e513)
- Bug 960317 - Remove cross-slide code from APZC. r=botond (b2a045dbc9)
- Bug 1231972 - Document how the apz.fling_friction pref is used. r=kats. DONTBUILD for comment change (c181588265)
- Bug 1221593 - Don't reset other axis' scroll position during APZ drag. r=kats (9de4e134c6)
- Bug 1219929 - Fix bad MouseInputData case. r=me (3630a3fcfa)
- Bug 1211506 - Respect the APZ lock ordering in AsyncPanZoomController::OnScrollWheel(). r=mstange (3f152ffabf)
- Bug 1229125 - Reset velocity in OnPanEnd if there's nowhere to scroll. r=botond (66ec61692a)
- fix misspatch (f7aea52b9d)
- Bug 1221186 - Don't clobber a fling-snap with a snap-to-where-we-are-now in the overscroll handoff chain. r=botond (7d4862bbe6)
- Bug 1204932 - When C++APZ is enabled, elements that are zoomed with double tap should be centered. r=botond (b9e02a24b4)
- Bug 1141884 - Rename ResetInputState and make it only apply to touch events. r=botond (aab239f51a)
- Bug 1229125 - Correct velocity computation for pan gesture events. r=botond (b1f11b2e04)
- Bug 1228559 - get MSG by audio channel type. r=roc (0e5e32f9bb)
- Bug 1191207 - cancel chrome checking (74bde1263e)
- Bug 1155469 - Mark nsTextEditorState::mTextCtrlElement as MOZ_NON_OWNING_REF; r=baku (7e6f4fa9d0)
- Bug 1218072 - crash in nsTextEditorState::FinishedRestoringSelection, r=smaug (c7811e18ea)
- bits of 1190258 (7f8fbbddfa)
- Bug 1130237: [MSE] P1. Only ever return a frame if we have data. r=gerald (1ed595a5f8)
- Bug 1130237: P2. Reset decoder state even if no decoder has been created yet. r=gerald (d352c0314b)
- Bug 1130237: [MSE] P3. Add mochitest testing behavior. r=gerald (ce2b710a7e)
- Bug 1229987: [MSE] P1. Ensure next random access point properly calculated after seek. r=gerald (d9a435f0b5)

dom/html/nsTextEditorState.cpp

@@ -110,7 +110,10 @@ public:
       }
       mTextEditorState->mSelectionRestoreEagerInit = false;
     }
-    mTextEditorState->FinishedRestoringSelection();
+
+    if (mTextEditorState) {
+      mTextEditorState->FinishedRestoringSelection();
+    }
     return NS_OK;
   }