Allow CopyFromBackingStore to fallback to copying from the renderer side if the accelerated surface…

content/renderer/render_widget.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 "content/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 303 matching lines @@
     IPC_MESSAGE_HANDLER(ViewMsg_Repaint, OnRepaint)
     IPC_MESSAGE_HANDLER(ViewMsg_SmoothScrollCompleted, OnSmoothScrollCompleted)
     IPC_MESSAGE_HANDLER(ViewMsg_SetTextDirection, OnSetTextDirection)
     IPC_MESSAGE_HANDLER(ViewMsg_Move_ACK, OnRequestMoveAck)
     IPC_MESSAGE_HANDLER(ViewMsg_ScreenInfoChanged, OnScreenInfoChanged)
     IPC_MESSAGE_HANDLER(ViewMsg_UpdateScreenRects, OnUpdateScreenRects)
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(ViewMsg_ImeBatchStateChanged, OnImeBatchStateChanged)
     IPC_MESSAGE_HANDLER(ViewMsg_ShowImeIfNeeded, OnShowImeIfNeeded)
 #endif
+    IPC_MESSAGE_HANDLER(ViewMsg_Snapshot, OnSnapshot)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 bool RenderWidget::Send(IPC::Message* message) {
   // Don't send any messages after the browser has told us to close, and filter
   // most outgoing messages while swapped out.
   if ((is_swapped_out_ &&
        !SwappedOutMessages::CanSendWhileSwappedOut(message)) ||
@@ skipping 1479 matching lines @@
   // Paint the entire thing (using original bounds, not scaled bounds).
   PaintRect(orig_bounds, orig_bounds.origin(), canvas.get());
   canvas->restore();
 
   // Return the widget to its previous size.
   webwidget_->resize(old_size);
 
   Send(new ViewHostMsg_PaintAtSize_ACK(routing_id_, tag, bounds.size()));
 }
 
+void RenderWidget::OnSnapshot(const gfx::Rect& src_subrect) {
+  SkBitmap snapshot;
+
+  if (OnSnapshotHelper(src_subrect, &snapshot)) {
+    Send(new ViewHostMsg_Snapshot(routing_id(), true, snapshot));
+  } else {
+    Send(new ViewHostMsg_Snapshot(routing_id(), false, SkBitmap()));
+  }
+}
+
+bool RenderWidget::OnSnapshotHelper(const gfx::Rect& src_subrect,
+                                    SkBitmap* snapshot) {
+  base::TimeTicks beginning_time = base::TimeTicks::Now();
+
+  if (!webwidget_ || src_subrect.IsEmpty())
+    return false;
+
+  gfx::Rect viewport_size = gfx::IntersectRects(
+      src_subrect, gfx::Rect(physical_backing_size_));
+
+  skia::RefPtr<SkCanvas> canvas = skia::AdoptRef(
+      skia::CreatePlatformCanvas(viewport_size.width(),
+                                 viewport_size.height(),
+                                 true,
+                                 NULL,
+                                 skia::RETURN_NULL_ON_FAILURE));
+  if (!canvas.get())
+    return false;
+
+  canvas->save();
+  webwidget_->layout();
+
+  PaintRect(viewport_size, viewport_size.origin(), canvas.get());
+  canvas->restore();
+
+  const SkBitmap& bitmap = skia::GetTopDevice(*canvas)->accessBitmap(false);
+  if (!bitmap.copyTo(snapshot, SkBitmap::kARGB_8888_Config))
+    return false;
+
+  UMA_HISTOGRAM_TIMES("Renderer4.Snapshot",
+                      base::TimeTicks::Now() - beginning_time);
+  return true;
+}
+
 void RenderWidget::OnRepaint(const gfx::Size& size_to_paint) {
   // During shutdown we can just ignore this message.
   if (!webwidget_)
     return;
 
   set_next_paint_is_repaint_ack();
   if (is_accelerated_compositing_active_) {
     if (compositor_)
       compositor_->setNeedsRedraw();
     scheduleComposite();
@@ skipping 423 matching lines @@
 
   if (!context->Initialize(
           attributes,
           false /* bind generates resources */,
           CAUSE_FOR_GPU_LAUNCH_WEBGRAPHICSCONTEXT3DCOMMANDBUFFERIMPL_INITIALIZE))
     return NULL;
   return context.release();
 }
 
 }  // namespace content