Adds support for showing the match preview on views. It's behind the

chrome/browser/tab_contents/match_preview.cc

Index: chrome/browser/tab_contents/match_preview.cc
diff --git a/chrome/browser/tab_contents/match_preview.cc b/chrome/browser/tab_contents/match_preview.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3c0c43e1eb027c24f20ca65c3da2f3760c03a8a6
--- /dev/null
+++ b/chrome/browser/tab_contents/match_preview.cc
@@ -0,0 +1,192 @@
+// Copyright (c) 2010 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/tab_contents/match_preview.h"
+
+#include <algorithm>
+
+#include "base/command_line.h"
+#include "chrome/browser/tab_contents/navigation_controller.h"
+#include "chrome/browser/tab_contents/navigation_entry.h"
+#include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/browser/tab_contents/tab_contents_delegate.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/common/notification_service.h"
+#include "chrome/common/page_transition_types.h"
+#include "chrome/common/renderer_preferences.h"
+#include "ipc/ipc_message.h"
+
+class MatchPreview::TabContentsDelegateImpl : public TabContentsDelegate {
+ public:
+  explicit TabContentsDelegateImpl(MatchPreview* match_preview)
+      : match_preview_(match_preview) {
+  }
+
+  virtual void OpenURLFromTab(TabContents* source,
+                              const GURL& url, const GURL& referrer,
+                              WindowOpenDisposition disposition,
+                              PageTransition::Type transition) {}
+  virtual void NavigationStateChanged(const TabContents* source,
+                                      unsigned changed_flags) {}
+  virtual void AddNewContents(TabContents* source,
+                              TabContents* new_contents,
+                              WindowOpenDisposition disposition,
+                              const gfx::Rect& initial_pos,
+                              bool user_gesture) {}
+  virtual void ActivateContents(TabContents* contents) {
+    match_preview_->CommitCurrentPreview();
+  }
+  virtual void LoadingStateChanged(TabContents* source) {}
+  virtual void CloseContents(TabContents* source) {}
+  virtual void MoveContents(TabContents* source, const gfx::Rect& pos) {}
+  virtual void DetachContents(TabContents* source) {}
+  virtual bool IsPopup(const TabContents* source) const {
+    return false;
+  }
+  virtual TabContents* GetConstrainingContents(TabContents* source) {
+    return NULL;
+  }
+  virtual void ToolbarSizeChanged(TabContents* source, bool is_animating) {}
+  virtual void URLStarredChanged(TabContents* source, bool starred) {}
+  virtual void UpdateTargetURL(TabContents* source, const GURL& url) {}
+  virtual void ContentsMouseEvent(
+      TabContents* source, const gfx::Point& location, bool motion) {}
+  virtual void ContentsZoomChange(bool zoom_in) {}
+  virtual void OnContentSettingsChange(TabContents* source) {}
+  virtual bool IsApplication() const { return false; }
+  virtual void ConvertContentsToApplication(TabContents* source) {}
+  virtual bool CanReloadContents(TabContents* source) const { return true; }
+  virtual gfx::Rect GetRootWindowResizerRect() const {
+    return match_preview_->host_->delegate() ?
+        match_preview_->host_->delegate()->GetRootWindowResizerRect() :
+        gfx::Rect();
+  }
+  virtual void ShowHtmlDialog(HtmlDialogUIDelegate* delegate,
+                              gfx::NativeWindow parent_window) {}
+  virtual void BeforeUnloadFired(TabContents* tab,
+                                 bool proceed,
+                                 bool* proceed_to_fire_unload) {}
+  virtual void ForwardMessageToExternalHost(const std::string& message,
+                                            const std::string& origin,
+                                            const std::string& target) {}
+  virtual bool IsExternalTabContainer() const { return false; }
+  virtual void SetFocusToLocationBar(bool select_all) {}
+  virtual void RenderWidgetShowing() {}
+  virtual ExtensionFunctionDispatcher* CreateExtensionFunctionDispatcher(
+      RenderViewHost* render_view_host,
+      const std::string& extension_id) {
+    return NULL;
+  }
+  virtual bool TakeFocus(bool reverse) { return false; }
+  virtual void SetTabContentBlocked(TabContents* contents, bool blocked) {}
+  virtual void TabContentsFocused(TabContents* tab_content) {
+    match_preview_->CommitCurrentPreview();
+  }
+  virtual int GetExtraRenderViewHeight() const { return 0; }
+  virtual bool CanDownload(int request_id) { return false; }
+  virtual void OnStartDownload(DownloadItem* download, TabContents* tab) {}
+  virtual bool HandleContextMenu(const ContextMenuParams& params) {
+    return false;
+  }
+  virtual bool ExecuteContextMenuCommand(int command) {
+    return false;
+  }
+  virtual void ConfirmAddSearchProvider(const TemplateURL* template_url,
+                                        Profile* profile) {}
+  virtual void ShowPageInfo(Profile* profile,
+                            const GURL& url,
+                            const NavigationEntry::SSLStatus& ssl,
+                            bool show_history) {}
+  virtual bool PreHandleKeyboardEvent(const NativeWebKeyboardEvent& event,
+                                      bool* is_keyboard_shortcut) {
+    return false;
+  }
+  virtual void HandleKeyboardEvent(const NativeWebKeyboardEvent& event) {}
+  virtual void ShowRepostFormWarningDialog(TabContents* tab_contents) {}
+  virtual void ShowContentSettingsWindow(ContentSettingsType content_type) {}
+  virtual void ShowCollectedCookiesDialog(TabContents* tab_contents) {}
+  virtual bool OnGoToEntryOffset(int offset) { return false; }
+  virtual bool ShouldAddNavigationsToHistory() const { return false; }
+  virtual void OnDidGetApplicationInfo(TabContents* tab_contents,
+                                       int32 page_id) {}
+  virtual Browser* GetBrowser() { return NULL; }
+  virtual gfx::NativeWindow GetFrameNativeWindow() {
+    return match_preview_->host_->delegate() ?
+        match_preview_->host_->delegate()->GetFrameNativeWindow() : NULL;
+  }
+  virtual void TabContentsCreated(TabContents* new_contents) {}
+  virtual bool infobars_enabled() { return false; }
+  virtual bool ShouldEnablePreferredSizeNotifications() { return false; }
+  virtual void UpdatePreferredSize(const gfx::Size& pref_size) {}
+  virtual void ContentTypeChanged(TabContents* source) {}
+
+ private:
+  MatchPreview* match_preview_;
+
+  DISALLOW_COPY_AND_ASSIGN(TabContentsDelegateImpl);
+};
+
+MatchPreview::MatchPreview(TabContents* host) : host_(host) {
+  delegate_.reset(new TabContentsDelegateImpl(this));
+}
+
+MatchPreview::~MatchPreview() {
+  // Delete the TabContents before the delegate as the TabContents holds a
+  // reference to the delegate.
+  preview_contents_.reset(NULL);
+}
+
+// static
+bool MatchPreview::IsEnabled() {
+  static bool enabled = false;
+  static bool checked = false;
+  if (!checked) {
+    checked = true;
+    enabled = CommandLine::ForCurrentProcess()->HasSwitch(
+        switches::kEnableMatchPreview);
+  }
+  return enabled;
+}
+
+void MatchPreview::Update(const GURL& url) {
+  if (url_ == url)
+    return;
+
+  url_ = url;
+
+  if (url_.is_empty() || !url_.is_valid()) {
+    DestroyPreviewContents();
+    return;
+  }
+
+  if (!preview_contents_.get()) {
+    preview_contents_.reset(
+        new TabContents(host_->profile(), NULL, MSG_ROUTING_NONE, NULL));
+    preview_contents_->set_delegate(delegate_.get());
+    NotificationService::current()->Notify(
+        NotificationType::MATCH_PREVIEW_TAB_CONTENTS_CREATED,
+        Source<TabContents>(host_),
+        NotificationService::NoDetails());
+  }
+
+  // TODO: figure out transition type.
+  preview_contents_->controller().LoadURL(url, GURL(),
+                                          PageTransition::GENERATED);
+}
+
+void MatchPreview::DestroyPreviewContents() {
+  url_ = GURL();
+  preview_contents_.reset(NULL);
+}
+
+void MatchPreview::CommitCurrentPreview() {
+  DCHECK(preview_contents_.get());
+  if (host_->delegate())
+    host_->delegate()->CommitMatchPreview(host_);
+}
+
+TabContents* MatchPreview::ReleasePreviewContents() {
+  url_ = GURL();
+  return preview_contents_.release();
+}