Add abstractions that let embedders drive tests of WebContents.

content/browser/tab_contents/web_drag_dest_mac_unittest.mm

 // 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/mac/scoped_nsautorelease_pool.h"
 #import "base/memory/scoped_nsobject.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "content/browser/renderer_host/test_render_view_host.h"
 #include "content/browser/tab_contents/test_tab_contents.h"
 #import "content/browser/tab_contents/web_drag_dest_mac.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #import "third_party/mozilla/NSPasteboard+Utils.h"
 #import "ui/base/dragdrop/cocoa_dnd_util.h"
 #import "ui/base/test/ui_cocoa_test_helper.h"
 #include "webkit/glue/webdropdata.h"
 
+using content::RenderViewHostImplTestHarness;
+
 namespace {
 NSString* const kCrCorePasteboardFlavorType_url =
     @"CorePasteboardFlavorType 0x75726C20"; // 'url '  url
 NSString* const kCrCorePasteboardFlavorType_urln =
     @"CorePasteboardFlavorType 0x75726C6E"; // 'urln'  title
 }  // namespace
 
-class WebDragDestTest : public RenderViewHostTestHarness {
+class WebDragDestTest : public RenderViewHostImplTestHarness {
  public:
   virtual void SetUp() {
-    RenderViewHostTestHarness::SetUp();
+    RenderViewHostImplTestHarness::SetUp();
     drag_dest_.reset([[WebDragDest alloc] initWithTabContents:contents()]);
   }
 
   void PutURLOnPasteboard(NSString* urlString, NSPasteboard* pboard) {
     [pboard declareTypes:[NSArray arrayWithObject:NSURLPboardType]
                    owner:nil];
     NSURL* url = [NSURL URLWithString:urlString];
     EXPECT_TRUE(url);
     [url writeToPasteboard:pboard];
   }
@@ skipping 114 matching lines @@
   NSString* textString = @"hi there";
   [pboard setString:htmlString forType:NSHTMLPboardType];
   [pboard setString:textString forType:NSStringPboardType];
   [drag_dest_ populateWebDropData:&data fromPasteboard:pboard];
   EXPECT_EQ(data.url.spec(), "http://www.google.com/");
   EXPECT_EQ(base::SysNSStringToUTF16(textString), data.plain_text);
   EXPECT_EQ(base::SysNSStringToUTF16(htmlString), data.text_html);
 
   [pboard releaseGlobally];
 }