fix(datepicker): compilation errors with ViewEngine

Fixes a few compilation errors that only happen when the date range picker is compiled with `ViewEngine`.

Author: crisbeto

src/material/datepicker/date-range-input-parts.ts

@@ -41,13 +41,15 @@ import {BooleanInput} from '@angular/cdk/coercion';
 import {BACKSPACE} from '@angular/cdk/keycodes';
 import {MatDatepickerInputBase, DateFilterFn} from './datepicker-input-base';
 import {DateRange, MatDateSelectionModel} from './date-selection-model';
+import {MatDateRangePicker} from './date-range-picker';
 
 /** Parent component that should be wrapped around `MatStartDate` and `MatEndDate`. */
 export interface MatDateRangeInputParent<D> {
   id: string;
   min: D | null;
   max: D | null;
   dateFilter: DateFilterFn<D>;
+  rangePicker: MatDateRangePicker<D>;
   _startInput: MatDateRangeInputPartBase<D>;
   _endInput: MatDateRangeInputPartBase<D>;
   _groupDisabled: boolean;
@@ -138,12 +140,12 @@ abstract class MatDateRangeInputPartBase<D>
   }
 
   /** Gets the minimum date from the range input. */
-  protected _getMinDate() {
+  _getMinDate() {
     return this._rangeInput.min;
   }
 
   /** Gets the maximum date from the range input. */
-  protected _getMaxDate() {
+  _getMaxDate() {
     return this._rangeInput.max;
   }
 

src/material/datepicker/datepicker-input-base.ts

@@ -174,10 +174,10 @@ export abstract class MatDatepickerInputBase<S, D = ExtractDateTypeFromSelection
   }
 
   /** Gets the minimum date for the input. Used for validation. */
-  protected abstract _getMinDate(): D | null;
+  abstract _getMinDate(): D | null;
 
   /** Gets the maximum date for the input. Used for validation. */
-  protected abstract _getMaxDate(): D | null;
+  abstract _getMaxDate(): D | null;
 
   /** Gets the date filter function. Used for validation. */
   protected abstract _getDateFilter(): DateFilterFn<D> | undefined;

src/material/datepicker/datepicker-input.ts

@@ -162,12 +162,12 @@ export class MatDatepickerInput<D> extends MatDatepickerInputBase<D | null, D>
   }
 
   /** Gets the input's minimum date. */
-  protected _getMinDate() {
+  _getMinDate() {
     return this._min;
   }
 
   /** Gets the input's maximum date. */
-  protected _getMaxDate() {
+  _getMaxDate() {
     return this._max;
   }
 

tools/public_api_guard/material/datepicker.d.ts

@@ -217,8 +217,8 @@ export declare class MatDatepickerInput<D> extends MatDatepickerInputBase<D | nu
     constructor(elementRef: ElementRef<HTMLInputElement>, dateAdapter: DateAdapter<D>, dateFormats: MatDateFormats, _formField: MatFormField);
     protected _assignValueToModel(value: D | null): void;
     protected _getDateFilter(): DateFilterFn<D | null>;
-    protected _getMaxDate(): D | null;
-    protected _getMinDate(): D | null;
+    _getMaxDate(): D | null;
+    _getMinDate(): D | null;
     protected _getValueFromModel(modelValue: D | null): D | null;
     protected _openPopup(): void;
     getConnectedOverlayOrigin(): ElementRef;