Create c/b/ui/cocoa/test and move test files to there

chrome/browser/ui/cocoa/history_overlay_controller_unittest.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/history_overlay_controller.h"
 
-#import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
+#import "chrome/browser/ui/cocoa/test/cocoa_test_helper.h"
 
 class HistoryOverlayControllerTest : public CocoaTest {
  public:
   void SetUp() override {
     CocoaTest::SetUp();
 
     // The overlay controller shows the panel as a subview of the given view.
     test_view_.reset([[NSView alloc] initWithFrame:NSMakeRect(10, 10, 10, 10)]);
 
     // We add it to the test_window for authenticity.
@@ skipping 15 matching lines @@
   base::scoped_nsobject<HistoryOverlayController> controller(
       [[HistoryOverlayController alloc] initForMode:kHistoryOverlayModeBack]);
   [controller showPanelForView:test_view()];
   EXPECT_EQ(1u, [[test_view() subviews] count]);
 
   // We expect the view to be removed from its superview immediately
   // after dismiss, even though it may still be animating a fade out.
   [controller dismiss];
   EXPECT_EQ(0u, [[test_view() subviews] count]);
 }