Support in-browser thumbnailing on Windows XP.

chrome/browser/tab_contents/thumbnail_generator.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 "chrome/browser/tab_contents/thumbnail_generator.h"
 
 #include <algorithm>
 #include <map>
 
 #include "base/bind.h"
@@ skipping 14 matching lines @@
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "googleurl/src/gurl.h"
 #include "skia/ext/image_operations.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/skbitmap_operations.h"
 
+#if defined(OS_WIN)
+#include "base/win/windows_version.h"
+#endif
+
 // Overview
 // --------
 // This class provides current thumbnails for tabs. The simplest operation is
 // when a request for a thumbnail comes in, to grab the backing store and make
 // a smaller version of that. Clients of the class can send such a request by
 // AskForSnapshot().
 //
 // The class also provides a service for updating thumbnails to be used in
 // "Most visited" section of the new tab page. The service can be started
 // by StartThumbnailing(). The current algorithm of the service is as
@@ skipping 133 matching lines @@
 
   if (registrar_.IsEmpty()) {
     // Even though we deal in RenderWidgetHosts, we only care about its
     // subclass, RenderViewHost when it is in a tab. We don't make thumbnails
     // for RenderViewHosts that aren't in tabs, or RenderWidgetHosts that
     // aren't views like select popups.
     registrar_.Add(this, content::NOTIFICATION_RENDER_VIEW_HOST_CREATED_FOR_TAB,
                    content::Source<WebContents>(web_contents));
     registrar_.Add(this, content::NOTIFICATION_WEB_CONTENTS_DISCONNECTED,
                    content::Source<WebContents>(web_contents));
+    web_contents_weak_factory_.reset(
+        new base::WeakPtrFactory<WebContents>(web_contents));
   }
 }
 
 void ThumbnailGenerator::MonitorRenderer(RenderWidgetHost* renderer,
                                          bool monitor) {
   content::Source<RenderWidgetHost> renderer_source =
       content::Source<RenderWidgetHost>(renderer);
   bool currently_monitored =
       registrar_.IsRegistered(
         this,
@@ skipping 234 matching lines @@
     }
   }
 
   SkBitmap clipped_bitmap;
   bitmap.extractSubset(&clipped_bitmap, src_rect);
   return clipped_bitmap;
 }
 
 void ThumbnailGenerator::UpdateThumbnailIfNecessary(
     WebContents* web_contents) {
-  content::RenderWidgetHostView* view = web_contents->GetRenderWidgetHostView();
-  if (!view)
-    return;
-  bool surface_available = view->IsSurfaceAvailableForCopy();
-  // Skip if we can't update the thumbnail.
-  if (!surface_available)
-    return;
   // Skip if a pending entry exists. WidgetHidden can be called while navigaing
   // pages and this is not a timing when thumbnails should be generated.
   if (web_contents->GetController().GetPendingEntry())
     return;
   const GURL& url = web_contents->GetURL();
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
   history::TopSites* top_sites = profile->GetTopSites();
   // Skip if we don't need to update the thumbnail.
   if (!ShouldUpdateThumbnail(profile, top_sites, url))
@@ skipping 29 matching lines @@
   VLOG(1) << "Thumbnail taken for " << url << ": " << score.ToString();
 }
 
 void ThumbnailGenerator::AsyncUpdateThumbnail(
     WebContents* web_contents) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   RenderWidgetHost* render_widget_host = web_contents->GetRenderViewHost();
   content::RenderWidgetHostView* view = render_widget_host->GetView();
   if (!view)
     return;
+  if (!view->IsSurfaceAvailableForCopy()) {
+#if defined(OS_WIN)
+    // On Windows XP, neither the backing store nor the compositing surface is
+    // available in the browser when accelerated compositing is active, so ask
+    // the renderer to send a snapshot for creating the thumbnail.
+    if (base::win::GetVersion() < base::win::VERSION_VISTA) {
+      gfx::Size view_size =
+          render_widget_host->GetView()->GetViewBounds().size();
+      AskForSnapshot(render_widget_host,
+                     base::Bind(&ThumbnailGenerator::UpdateThumbnailWithBitmap,
+                                weak_factory_.GetWeakPtr(),
+                                web_contents_weak_factory_->GetWeakPtr()),
+                     view_size,
+                     view_size);
+    }
+#endif
+    return;
+  }
 
-  const gfx::Size copy_size =
+  gfx::Size copy_size =
       GetCopySizeForThumbnail(view->GetViewBounds().size(),
                               gfx::Size(kThumbnailWidth, kThumbnailHeight));
   skia::PlatformCanvas* temp_canvas = new skia::PlatformCanvas;
-  web_contents_weak_factory_.reset(
-      new base::WeakPtrFactory<WebContents>(web_contents));
   render_widget_host->CopyFromBackingStore(
       gfx::Rect(), copy_size, temp_canvas,
-      base::Bind(&ThumbnailGenerator::AsyncUpdateThumbnailFinish,
+      base::Bind(&ThumbnailGenerator::UpdateThumbnailWithCanvas,
                  weak_factory_.GetWeakPtr(),
                  web_contents_weak_factory_->GetWeakPtr(),
                  base::Owned(temp_canvas)));
 }
 
-void ThumbnailGenerator::AsyncUpdateThumbnailFinish(
-    base::WeakPtr<WebContents> web_contents,
-    skia::PlatformCanvas* temp_canvas,
-    bool succeeded) {
+void ThumbnailGenerator::UpdateThumbnailWithBitmap(
+    const base::WeakPtr<WebContents>& web_contents,
+    const SkBitmap& bitmap) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  // The weak pointer can be invalidated by the subsequent AsyncUpdateThumbnail.
+  // The weak pointer is invalidated when the web contens is disconnected.
   if (!web_contents.get())
     return;
 
-  if (!succeeded)
+  if (bitmap.isNull() || bitmap.empty())
     return;
 
-  SkBitmap bmp_with_scrollbars =
-      skia::GetTopDevice(*temp_canvas)->accessBitmap(false);
   ClipResult clip_result;
-  SkBitmap thumbnail = CreateThumbnail(bmp_with_scrollbars,
+  SkBitmap thumbnail = CreateThumbnail(bitmap,
                                        kThumbnailWidth,
                                        kThumbnailHeight,
                                        ThumbnailGenerator::kClippedThumbnail,
                                        &clip_result);
   UpdateThumbnail(web_contents.get(), thumbnail, clip_result);
 }
 
+void ThumbnailGenerator::UpdateThumbnailWithCanvas(
+    const base::WeakPtr<WebContents>& web_contents,
+    skia::PlatformCanvas* temp_canvas,
+    bool succeeded) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  // The weak pointer is invalidated when the web contens is disconnected.
+  if (!web_contents.get())
+    return;
+
+  if (!succeeded)
+    return;
+
+  SkBitmap bmp_with_scrollbars =
+      skia::GetTopDevice(*temp_canvas)->accessBitmap(false);
+  UpdateThumbnailWithBitmap(web_contents, bmp_with_scrollbars);
+}
+
 bool ThumbnailGenerator::ShouldUpdateThumbnail(Profile* profile,
                                                history::TopSites* top_sites,
                                                const GURL& url) {
   if (!profile || !top_sites)
     return false;
   // Skip if it's in the incognito mode.
   if (profile->IsOffTheRecord())
     return false;
   // Skip if the given URL is not appropriate for history.
   if (!HistoryService::CanAddURL(url))
@@ skipping 18 matching lines @@
 
 void ThumbnailGenerator::DidStartLoading() {
   load_interrupted_ = false;
 }
 
 void ThumbnailGenerator::StopNavigation() {
   // This function gets called when the page loading is interrupted by the
   // stop button.
   load_interrupted_ = true;
 }