Fixing a crash due to calling [RWHVCocoa attributedSubstringForProposedRange] when there is no focu…

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index b67a5f3d160e4521c879bcdb7bf30b7fa005876a..d60da64073eb29024c09b027513251a0ad2e25d3 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -3097,7 +3097,10 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
   if (!selection)
     return nil;
 
-  if (!compositionInfo->range.is_empty()) {
+  if (compositionInfo && !compositionInfo->range.is_empty()) {
+    // This method might get called after TextInputState.type is reset to none,
+    // in which case there will be no composition range information
+    // (https://crbug.com/698672).
     expected_text = &markedText_;
     expected_range = compositionInfo->range;
   } else {