[iOS] Fix ios_chrome_unittests on iPad

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"
@@ skipping 359 matching lines @@
 
   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())
+    [cache handleLowMemory];
 
   BOOL expectedValue = YES;
   if (IsIPadIdiom()) {
     expectedValue = NO;
   }
   EXPECT_EQ(expectedValue, [cache hasImageInMemory:firstPinnedID]);
   EXPECT_EQ(expectedValue, [cache hasImageInMemory:secondPinnedID]);
 
   NSString* notPinnedID = [testSessions_ objectAtIndex:2];
   EXPECT_FALSE([cache hasImageInMemory:notPinnedID]);
@@ skipping 32 matching lines @@
 }
 
 // Same as previous test, except that all the color images are on disk,
 // rather than in memory.
 // Disabled due to the greyImage crash.  b/8048597
 TEST_F(SnapshotCacheTest, CreateGreyCacheFromDisk) {
   LoadAllColorImagesIntoCache(true);
 
   // Remove color images from in-memory cache.
   SnapshotCache* cache = GetSnapshotCache();
-  [cache handleLowMemory];
+
+  if (!IsIPadIdiom())
+    [cache handleLowMemory];
 
   // Request the creation of a grey image cache for all images.
   [cache createGreyCache:testSessions_];
 
   // Wait for them to be put into the grey image cache.
   WaitForGreyImagesInCache(kSessionCount);
 
   __block NSUInteger numberOfCallbacks = 0;
   for (NSUInteger i = 0; i < kSessionCount; ++i) {
     NSString* sessionID = [testSessions_ objectAtIndex:i];
@@ skipping 20 matching lines @@
   [sessionIDs addObject:[testSessions_ objectAtIndex:0]];
   [sessionIDs addObject:[testSessions_ objectAtIndex:1]];
   [sessionIDs addObject:[testSessions_ objectAtIndex:2]];
 
   SnapshotCache* cache = GetSnapshotCache();
 
   // Put 3 images in the cache.
   LoadColorImagesIntoCache(kNumImages, true);
   // Make sure the color images are only on disk, to ensure the background
   // thread is slow enough to queue up the requests.
-  [cache handleLowMemory];
+  if (!IsIPadIdiom())
+    [cache handleLowMemory];
 
   // Enable the grey image cache.
   [cache createGreyCache:sessionIDs];
 
   // Request the grey versions
   __block BOOL firstCallbackCalled = NO;
   __block BOOL secondCallbackCalled = NO;
   __block BOOL thirdCallbackCalled = NO;
   [cache greyImageForSessionID:[testSessions_ objectAtIndex:0]
                       callback:^(UIImage*) {
@@ skipping 50 matching lines @@
   CGContextRef context = UIGraphicsGetCurrentContext();
   UIImage* image = GenerateRandomImage(context);
   UIGraphicsEndImageContext();
 
   // Add the image to the cache then call handle low memory to ensure the image
   // is read from disk instead of the in-memory cache.
   SnapshotCache* cache = GetSnapshotCache();
   NSString* const kSession = @"foo";
   [cache setImage:image withSessionID:kSession];
   FlushRunLoops();  // ensure the file is written to disk.
-  [cache handleLowMemory];
+  if (!IsIPadIdiom())
+    [cache handleLowMemory];
 
   // Retrive the image and have the callback verify the size and scale.
   __block BOOL callbackComplete = NO;
   [cache retrieveImageForSessionID:kSession
                           callback:^(UIImage* imageFromDisk) {
                             EXPECT_EQ(image.size.width,
                                       imageFromDisk.size.width);
                             EXPECT_EQ(image.size.height,
                                       imageFromDisk.size.height);
                             EXPECT_EQ(image.scale, imageFromDisk.scale);
@@ skipping 15 matching lines @@
   CGContextRef context = UIGraphicsGetCurrentContext();
   UIImage* image = GenerateRandomImage(context);
   UIGraphicsEndImageContext();
 
   // Add the image to the cache then call handle low memory to ensure the image
   // is read from disk instead of the in-memory cache.
   SnapshotCache* cache = GetSnapshotCache();
   NSString* const kSession = @"foo";
   [cache setImage:image withSessionID:kSession];
   FlushRunLoops();  // ensure the file is written to disk.
-  [cache handleLowMemory];
+  if (!IsIPadIdiom())
+    [cache handleLowMemory];
 
   // Verify the file was writted with @2x in the file name.
   base::FilePath retinaFile = [SnapshotCache imagePathForSessionID:kSession];
   EXPECT_TRUE(base::PathExists(retinaFile));
 
   // Delete the image.
   [cache removeImageWithSessionID:kSession];
   FlushRunLoops();  // ensure the file is removed.
 
   EXPECT_FALSE(base::PathExists(retinaFile));
 }
 
 }  // namespace