Move nsimage_cache into base so that it can be accessed from outside of chrome

chrome/browser/cocoa/nsimage_cache.mm

-// Copyright (c) 2009 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.
-
-#include "chrome/browser/cocoa/nsimage_cache.h"
-
-#include "base/logging.h"
-#include "base/mac_util.h"
-
-// When C++ exceptions are disabled, the C++ library defines |try| and
-// |catch| so as to allow exception-expecting C++ code to build properly when
-// language support for exceptions is not present.  These macros interfere
-// with the use of |@try| and |@catch| in Objective-C files such as this one.
-// Undefine these macros here, after everything has been #included, since
-// there will be no C++ uses and only Objective-C uses from this point on.
-#undef try
-#undef catch
-
-namespace nsimage_cache {
-
-static NSMutableDictionary *image_cache = nil;
-
-NSImage *ImageNamed(NSString *name) {
-  DCHECK(name);
-
-  // NOTE: to make this thread safe, we'd have to sync on the cache and
-  // also force all the bundle calls on the main thread.
-
-  if (!image_cache) {
-    image_cache = [[NSMutableDictionary alloc] init];
-    DCHECK(image_cache);
-  }
-
-  NSImage *result = [image_cache objectForKey:name];
-  if (!result) {
-    DLOG_IF(INFO, [[name pathExtension] length] == 0)
-        << "Suggest including the extension in the image name";
-
-    NSString *path = [mac_util::MainAppBundle() pathForImageResource:name];
-    if (path) {
-      @try {
-        result = [[[NSImage alloc] initWithContentsOfFile:path] autorelease];
-        if (result)
-          [image_cache setObject:result forKey:name];
-      }
-      @catch (id err) {
-        DLOG(ERROR) << "Failed to load the image for name '"
-            << [name UTF8String] << "' from path '" << [path UTF8String]
-            << "', error: " << [err description];
-        result = nil;
-      }
-    }
-  }
-
-  // TODO: if we ever limit the cache size, this should retain & autorelease
-  // the image.
-  return result;
-}
-
-void Clear(void) {
-  // NOTE: to make this thread safe, we'd have to sync on the cache.
-  [image_cache removeAllObjects];
-}
-
-}  // namespace nsimage_cache