Add non-member non-mutating methods for common gfx::Rect operations.

webkit/plugins/webview_plugin.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 "webkit/plugins/webview_plugin.h"
 
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCursorInfo.h"
@@ skipping 102 matching lines @@
 
 NPObject* WebViewPlugin::scriptableObject() {
   return NULL;
 }
 
 bool WebViewPlugin::getFormValue(WebString& value) {
   return false;
 }
 
 void WebViewPlugin::paint(WebCanvas* canvas, const WebRect& rect) {
-  gfx::Rect paintRect = rect_;
-  paintRect.Intersect(rect);
+  gfx::Rect paintRect = gfx::IntersectRects(rect_, rect);
   if (paintRect.IsEmpty())
     return;
 
   paintRect.Offset(-rect_.x(), -rect_.y());
 
   canvas->translate(SkIntToScalar(rect_.x()), SkIntToScalar(rect_.y()));
   canvas->save();
 
   web_view_->layout();
   web_view_->paint(canvas, paintRect);
@@ skipping 99 matching lines @@
   return error;
 }
 
 void WebViewPlugin::didReceiveResponse(WebFrame* frame,
                                        unsigned identifier,
                                        const WebURLResponse& response) {
   WebFrameClient::didReceiveResponse(frame, identifier, response);
 }
 
 }  // namespace webkit