Restore SnapshotTabHelper temporarily

chrome/renderer/chrome_render_view_observer.cc

Index: chrome/renderer/chrome_render_view_observer.cc
diff --git a/chrome/renderer/chrome_render_view_observer.cc b/chrome/renderer/chrome_render_view_observer.cc
index 48651a7b8370133c3b8fac0b6ab1831db5e609d7..020979a3710c207c28ebc86058bb83875bfbdc12 100644
--- a/chrome/renderer/chrome_render_view_observer.cc
+++ b/chrome/renderer/chrome_render_view_observer.cc
@@ -194,6 +194,7 @@ bool ChromeRenderViewObserver::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ChromeRenderViewObserver, message)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_WebUIJavaScript, OnWebUIJavaScript)
+    IPC_MESSAGE_HANDLER(ChromeViewMsg_CaptureSnapshot, OnCaptureSnapshot)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_HandleMessageFromExternalHost,
                         OnHandleMessageFromExternalHost)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_JavaScriptStressTestControl,
@@ -235,6 +236,24 @@ void ChromeRenderViewObserver::OnWebUIJavaScript(
   webui_javascript_->notify_result = notify_result;
 }
 
+void ChromeRenderViewObserver::OnCaptureSnapshot() {
+  SkBitmap snapshot;
+  bool error = false;
+
+  WebFrame* main_frame = render_view()->GetWebView()->mainFrame();
+  if (!main_frame)
+    error = true;
+
+  if (!error && !CaptureSnapshot(render_view()->GetWebView(), &snapshot))
+    error = true;
+
+  DCHECK(error == snapshot.empty()) <<
+      "Snapshot should be empty on error, non-empty otherwise.";
+
+  // Send the snapshot to the browser process.
+  Send(new ChromeViewHostMsg_Snapshot(routing_id(), snapshot));
+}
+
 void ChromeRenderViewObserver::OnHandleMessageFromExternalHost(
     const std::string& message,
     const std::string& origin,
@@ -776,6 +795,35 @@ void ChromeRenderViewObserver::CaptureText(WebFrame* frame,
   }
 }
 
+bool ChromeRenderViewObserver::CaptureSnapshot(WebView* view,
+                                               SkBitmap* snapshot) {
+  base::TimeTicks beginning_time = base::TimeTicks::Now();
+
+  view->layout();
+  const WebSize& size = view->size();
+
+  skia::RefPtr<SkCanvas> canvas = skia::AdoptRef(
+      skia::CreatePlatformCanvas(
+          size.width, size.height, true, NULL, skia::RETURN_NULL_ON_FAILURE));
+  if (!canvas)
+    return false;
+
+  view->paint(webkit_glue::ToWebCanvas(canvas.get()),
+              WebRect(0, 0, size.width, size.height));
+  // TODO: Add a way to snapshot the whole page, not just the currently
+  // visible part.
+
+  SkDevice* device = skia::GetTopDevice(*canvas);
+
+  const SkBitmap& bitmap = device->accessBitmap(false);
+  if (!bitmap.copyTo(snapshot, SkBitmap::kARGB_8888_Config))
+    return false;
+
+  UMA_HISTOGRAM_TIMES("Renderer4.Snapshot",
+                  base::TimeTicks::Now() - beginning_time);
+  return true;
+}
+
 ExternalHostBindings* ChromeRenderViewObserver::GetExternalHostBindings() {
   if (!external_host_bindings_.get()) {
     external_host_bindings_.reset(new ExternalHostBindings(