Fix memory leak in SaveToDisk.

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/location.h"
 #include "base/mac/bind_objc_block.h"
+#include "base/mac/scoped_cftyperef.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/run_loop.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/time/time.h"
 #import "ios/chrome/browser/snapshots/snapshot_cache_internal.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"
@@ skipping 160 matching lines @@
     }
 
     if (byteOrder != kCGBitmapByteOrder32Host) {
       int lastChannel = (CGImageGetBitsPerPixel(cgImage) == 24) ? 2 : 3;
       *red = lastChannel - *red;
       *green = lastChannel - *green;
       *blue = lastChannel - *blue;
     }
   }
 
-  const char* GetPixelData(CGImageRef cgImage) {
-    CFDataRef data = CGDataProviderCopyData(CGImageGetDataProvider(cgImage));
-    return reinterpret_cast<const char*>(CFDataGetBytePtr(data));
-  }
-
   void TriggerMemoryWarning() {
     // _performMemoryWarning is a private API and must not be compiled into
     // official builds.
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wundeclared-selector"
     [[UIApplication sharedApplication]
         performSelector:@selector(_performMemoryWarning)];
 #pragma clang diagnostic pop
   }
 
@@ skipping 55 matching lines @@
     NSString* sessionID = [testSessions_ objectAtIndex:i];
 
     base::FilePath path([SnapshotCache imagePathForSessionID:sessionID]);
     EXPECT_TRUE(base::PathExists(path));
 
     // Check image colors by comparing the first pixel against the reference
     // image.
     UIImage* image =
         [UIImage imageWithContentsOfFile:base::SysUTF8ToNSString(path.value())];
     CGImageRef cgImage = [image CGImage];
-    const char* pixels = GetPixelData(cgImage);
+    base::ScopedCFTypeRef<CFDataRef> pixelData(
+        CGDataProviderCopyData(CGImageGetDataProvider(cgImage)));
+    const char* pixels =
+        reinterpret_cast<const char*>(CFDataGetBytePtr(pixelData));
     EXPECT_TRUE(pixels);
 
     UIImage* referenceImage = [testImages_ objectAtIndex:i];
     CGImageRef referenceCgImage = [referenceImage CGImage];
-    const char* referencePixels = GetPixelData(referenceCgImage);
+    base::ScopedCFTypeRef<CFDataRef> referenceData(
+        CGDataProviderCopyData(CGImageGetDataProvider(referenceCgImage)));
+    const char* referencePixels =
+        reinterpret_cast<const char*>(CFDataGetBytePtr(referenceData));
     EXPECT_TRUE(referencePixels);
 
     if (pixels != nil && referencePixels != nil) {
       // Color components may not be in the same order,
       // because of writing to disk and reloading.
       int red, green, blue;
       ComputeColorComponents(cgImage, &red, &green, &blue);
 
       int referenceRed, referenceGreen, referenceBlue;
       ComputeColorComponents(referenceCgImage, &referenceRed, &referenceGreen,
@@ skipping 271 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