build: remove unused tslint rule (#8453)

Since the `noViewEncapsulation` rule logic is now in the `validateDecorators`, we don't have to keep the file around anymore.

tools/tslint-rules/noViewEncapsulationRule.ts

@@ -1,59 +0,0 @@
-import * as path from 'path';
-import * as ts from 'typescript';
-import * as Lint from 'tslint';
-import * as minimatch from 'minimatch';
-
-const ERROR_MESSAGE = 'Components must turn off view encapsulation.';
-
-// TODO(crisbeto): combine this with the OnPush rule when it gets in.
-
-/**
- * Rule that enforces that view encapsulation is turned off on all components.
- * Files can be whitelisted via `"no-view-encapsulation": [true, "\.spec\.ts$"]`.
- */
-export class Rule extends Lint.Rules.AbstractRule {
-  apply(sourceFile: ts.SourceFile) {
-    return this.applyWithWalker(new Walker(sourceFile, this.getOptions()));
-  }
-}
-
-class Walker extends Lint.RuleWalker {
-
-  /** Whether the walker should check the current source file. */
-  private _enabled: boolean;
-
-  constructor(sourceFile: ts.SourceFile, options: Lint.IOptions) {
-    super(sourceFile, options);
-
-    // Globs that are used to determine which files to lint.
-    const fileGlobs = options.ruleArguments || [];
-
-    // Relative path for the current TypeScript source file.
-    const relativeFilePath = path.relative(process.cwd(), sourceFile.fileName);
-
-    // Whether the file should be checked at all.
-    this._enabled = fileGlobs.some(p => minimatch(relativeFilePath, p));
-  }
-
-  visitClassDeclaration(node: ts.ClassDeclaration) {
-    if (!this._enabled || !node.decorators) {
-      return;
-    }
-
-    node.decorators
-      .map(decorator => decorator.expression as any)
-      .filter(expression => expression.expression.getText() === 'Component')
-      .filter(expression => expression.arguments.length && expression.arguments[0].properties)
-      .forEach(expression => {
-        const hasTurnedOffEncapsulation = expression.arguments[0].properties.some((prop: any) => {
-          const value = prop.initializer.getText();
-          return prop.name.getText() === 'encapsulation' && value.endsWith('.None');
-        });
-
-        if (!hasTurnedOffEncapsulation) {
-          this.addFailureAtNode(expression.parent, ERROR_MESSAGE);
-        }
-      });
-  }
-
-}