Enable iPad Tab Switcher by default on iOS.

ios/chrome/browser/snapshots/snapshot_cache_unittest.mm

 // Copyright 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 "ios/chrome/browser/snapshots/snapshot_cache.h"
 
 #import <Foundation/Foundation.h>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/format_macros.h"
-#include "base/ios/ios_util.h"
 #include "base/location.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/run_loop.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/time/time.h"
 #include "ios/chrome/browser/experimental_flags.h"
 #include "ios/chrome/browser/ui/ui_util.h"
 #include "ios/web/public/test/test_web_thread_bundle.h"
 #include "ios/web/public/web_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest_mac.h"
 #include "testing/platform_test.h"
 
 static const NSUInteger kSessionCount = 10;
 static const NSUInteger kSnapshotPixelSize = 8;
 
 // Promote some implementation methods to public.

[sdefresne, 2016/02/25 10:08:09]

This is an anti-pattern. Please move this to snapshot_cache_internal.h and use
this from both this file and snapshot_cache.mm.

[jif, 2016/02/25 12:42:28]

Done.

 @interface SnapshotCache (Testing)
 + (base::FilePath)imagePathForSessionID:(NSString*)sessionID;
 + (base::FilePath)greyImagePathForSessionID:(NSString*)sessionID;
+- (BOOL)cacheIsEnabled;
+- (BOOL)useLRUCache;
 - (void)handleLowMemory;
 @end
 
 namespace {
 
 class SnapshotCacheTest : public PlatformTest {
  protected:
   // Build an array of session names and an array of UIImages filled with
   // random colors.
   void SetUp() override {
@@ skipping 172 matching lines @@
 TEST_F(SnapshotCacheTest, Cache) {
   // Don't run on tablets because color snapshots are not cached so this test
   // can't compare the UIImage pointers directly.
   if (IsIPadIdiom() && !experimental_flags::IsTabSwitcherEnabled()) {
     return;
   }
 
   SnapshotCache* cache = GetSnapshotCache();
 
   NSUInteger expectedCacheSize = kSessionCount;
-  if (experimental_flags::IsLRUSnapshotCacheEnabled())
+  if ([cache useLRUCache])
     expectedCacheSize = MIN(kSessionCount, [cache lruCacheMaxSize]);
 
   // Put all images in the cache.
   for (NSUInteger i = 0; i < expectedCacheSize; ++i) {
     UIImage* image = [testImages_ objectAtIndex:i];
     NSString* sessionID = [testSessions_ objectAtIndex:i];
     [cache setImage:image withSessionID:sessionID];
   }
 
   // Get images back.
@@ skipping 105 matching lines @@
     if (i == 0)
       EXPECT_TRUE(base::PathExists(path));
     else
       EXPECT_FALSE(base::PathExists(path));
   }
 }
 
 // Loads the color images into the cache, and pins two of them.  Ensures that
 // only the two pinned IDs remain in memory after a call to -handleLowMemory.
 TEST_F(SnapshotCacheTest, HandleLowMemory) {
-// TODO(droger): This test fails on iPad iOS8 device: http://crbug.com/455209
-#if !TARGET_IPHONE_SIMULATOR
-  if (IsIPadIdiom() && base::ios::IsRunningOnIOS8OrLater()) {
-    LOG(WARNING) << "Test disabled on iPad iOS8 device.";
-    return;
-  }
-#endif
-
   LoadAllColorImagesIntoCache(true);
 
   SnapshotCache* cache = GetSnapshotCache();
 
   NSString* firstPinnedID = [testSessions_ objectAtIndex:4];
   NSString* secondPinnedID = [testSessions_ objectAtIndex:6];
   NSMutableSet* set = [NSMutableSet set];
   [set addObject:firstPinnedID];
   [set addObject:secondPinnedID];
   cache.pinnedIDs = set;
+  [cache handleLowMemory];
 
-  if (!IsIPadIdiom() || experimental_flags::IsTabSwitcherEnabled())
-    [cache handleLowMemory];
-
-  BOOL expectedValue = YES;
-  if (IsIPadIdiom() && !experimental_flags::IsTabSwitcherEnabled())
-    expectedValue = NO;
-
-  EXPECT_EQ(expectedValue, [cache hasImageInMemory:firstPinnedID]);
-  EXPECT_EQ(expectedValue, [cache hasImageInMemory:secondPinnedID]);
+  EXPECT_EQ(YES, [cache hasImageInMemory:firstPinnedID]);
+  EXPECT_EQ(YES, [cache hasImageInMemory:secondPinnedID]);
 
   NSString* notPinnedID = [testSessions_ objectAtIndex:2];
   EXPECT_FALSE([cache hasImageInMemory:notPinnedID]);
 
   // Wait for the final image to be pulled off disk.
   FlushRunLoops();
 }
 
 // Tests that createGreyCache creates the grey snapshots in the background,
 // from color images in the in-memory cache.  When the grey images are all
@@ skipping 192 matching lines @@
   EXPECT_TRUE(base::PathExists(retinaFile));
 
   // Delete the image.
   [cache removeImageWithSessionID:kSession];
   FlushRunLoops();  // ensure the file is removed.
 
   EXPECT_FALSE(base::PathExists(retinaFile));
 }
 
 }  // namespace