Make the id used in IconMsg_DownloadFavicon unique

chrome/browser/favicon/favicon_handler_unittest.cc

 // 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.
 
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/favicon/favicon_handler.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
 #include "content/public/browser/invalidate_type.h"
 #include "content/public/browser/navigation_entry.h"
@@ skipping 134 matching lines @@
   explicit TestFaviconHandlerDelegate(WebContents* tab_contents)
       : tab_contents_(tab_contents) {
   }
 
   virtual NavigationEntry* GetActiveEntry() {
     ADD_FAILURE() << "TestFaviconHandlerDelegate::GetActiveEntry() "
                   << "should never be called in tests.";
     return NULL;
   }
 
-  virtual void StartDownload(int id, const GURL& url, int image_size) {
+  virtual int StartDownload(const GURL& url, int image_size) {
     ADD_FAILURE() << "TestFaviconHandlerDelegate::StartDownload() "
                   << "should never be called in tests.";
+    return -1;
   }
 
   virtual void NotifyFaviconUpdated() {
     tab_contents_->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB);
   }
 
  private:
   WebContents* tab_contents_;  // weak
 };
 
@@ skipping 776 matching lines @@
   EXPECT_EQ(0U, handler.image_urls().size());
 
   // Verify correct icon size chosen.
   EXPECT_EQ(icon_url_preferred1, handler.GetEntry()->GetFavicon().url);
   EXPECT_TRUE(handler.GetEntry()->GetFavicon().valid);
   EXPECT_FALSE(handler.GetEntry()->GetFavicon().bitmap.empty());
   EXPECT_EQ(gfx::kFaviconSize, handler.GetEntry()->GetFavicon().bitmap.width());
 }
 
 }  // namespace.