From 803e67b3b80a03fc75ae15274c764afc2c00ddfd Mon Sep 17 00:00:00 2001
From: crisbeto <crisbeto@abv.bg>
Date: Tue, 4 Sep 2018 21:35:19 +0200
Subject: [PATCH] fix(form-field): don't set up mutation observer on
 non-outline appearances

Currently we use a `MutationObserver` to update the label gap when the label content changes. This is unnecessary on any appearance aside from `outline`.
---
 src/cdk/observers/observe-content.ts | 6 +-----
 src/lib/form-field/form-field.html   | 1 +
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/cdk/observers/observe-content.ts b/src/cdk/observers/observe-content.ts
index 25c80b32adb4..baef9349ac45 100644
--- a/src/cdk/observers/observe-content.ts
+++ b/src/cdk/observers/observe-content.ts
@@ -145,11 +145,7 @@ export class CdkObserveContent implements AfterContentInit, OnDestroy {
   get disabled() { return this._disabled; }
   set disabled(value: any) {
     this._disabled = coerceBooleanProperty(value);
-    if (this._disabled) {
-      this._unsubscribe();
-    } else {
-      this._subscribe();
-    }
+    this._disabled ? this._unsubscribe() : this._subscribe();
   }
   private _disabled = false;
 
diff --git a/src/lib/form-field/form-field.html b/src/lib/form-field/form-field.html
index 8e4b28253ae6..e6c91f58a9e6 100644
--- a/src/lib/form-field/form-field.html
+++ b/src/lib/form-field/form-field.html
@@ -28,6 +28,7 @@
              read if it comes before the control in the DOM. -->
         <label class="mat-form-field-label"
                (cdkObserveContent)="updateOutlineGap()"
+               [cdkObserveContentDisabled]="appearance != 'outline'"
                [id]="_labelId"
                [attr.for]="_control.id"
                [attr.aria-owns]="_control.id"