remove bluriness fixes that aren't needed anymore

Author: mmalerba

src/lib/form-field/_form-field-box-theme.scss

@@ -45,9 +45,6 @@ $mat-form-field-box-dedupe: 0;
              scale($font-scale);
   width: 100% / $font-scale + $mat-form-field-box-dedupe;
 
-  // Prevent text bluriness when label is floating.
-  backface-visibility: initial;
-
   $mat-form-field-box-dedupe: $mat-form-field-box-dedupe + 0.00001 !global;
 }
 

src/lib/form-field/_form-field-theme.scss

@@ -109,9 +109,6 @@ $mat-form-field-dedupe: 0;
              scale($font-scale);
   width: 100% / $font-scale + $mat-form-field-dedupe;
 
-  // Prevent text bluriness when label is floating.
-  backface-visibility: initial;
-
   $mat-form-field-dedupe: $mat-form-field-dedupe + 0.00001 !global;
 }
 

src/lib/form-field/form-field-legacy.scss

@@ -9,13 +9,7 @@ $mat-form-field-legacy-underline-height: 1px !default;
 
 
 .mat-form-field-variant-legacy {
-  .mat-form-field-label-wrapper {
-    filter: initial;
-  }
-
   .mat-form-field-label {
-    backface-visibility: initial;
-
     transform: perspective(100px);
     -ms-transform: none;
   }

src/lib/form-field/form-field.scss

@@ -78,9 +78,6 @@ $mat-form-field-default-infix-width: 180px !default;
   height: 100%;
   overflow: hidden;
   pointer-events: none;  // We shouldn't catch mouse events (let them through).
-
-  // Helps prevent text jumpiness when transforming the label.
-  filter: blur(0);
 }
 
 // The label itself. This is invisible unless it is. The logic to show it is
@@ -108,9 +105,6 @@ $mat-form-field-default-infix-width: 180px !default;
   // Hide the label initially, and only show it when it's floating or the control is empty.
   display: none;
 
-  // Helps prevent text jumpiness when transforming the label.
-  backface-visibility: hidden;
-
   [dir='rtl'] & {
     transform-origin: 100% 0;
     left: auto;