Browser-wide audio mirroring for TabCapture API

content/browser/renderer_host/media/web_contents_video_capture_device.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.
 //
 // Implementation notes: This needs to work on a variety of hardware
 // configurations where the speed of the CPU and GPU greatly affect overall
 // performance.  Therefore, the process of capturing has been split up into a
 // pipeline of three stages.  Each stage executes on its own thread:
 //
 //   1. Capture: A bitmap is snapshotted/copied from the RenderView's backing
@@ skipping 34 matching lines @@
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback_forward.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string_number_conversions.h"
 #include "base/string_piece.h"
+#include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "base/time.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
+#include "content/public/common/media_stream_request.h"
 #include "media/base/bind_to_loop.h"
 #include "media/video/capture/video_capture_types.h"
 #include "skia/ext/image_operations.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/rect.h"
 
 // TODO(miu): The caller of Allocate() should use an appropriate heuristic to
 // determine the frame size.  For now, hard-code the capture device to 720p
@@ skipping 888 matching lines @@
   device_name_.unique_id = "-1:-1";
   capturer_->InitializeForTesting(test_source, destroy_cb);
 }
 
 WebContentsVideoCaptureDevice::~WebContentsVideoCaptureDevice() {
   DVLOG(2) << "WebContentsVideoCaptureDevice@" << this << " destroying.";
 }
 
 // static
 media::VideoCaptureDevice* WebContentsVideoCaptureDevice::Create(
-    const std::string& device_id) {
+    const std::string& device_id_param) {
+  DCHECK(StartsWithASCII(device_id_param,
+                         content::kMediaStreamTabDeviceScheme, true));
+  const std::string device_id = device_id_param.substr(
+    strlen(content::kMediaStreamTabDeviceScheme),
+    device_id_param.length());
+
   // Parse device_id into render_process_id and render_view_id.
   const size_t sep_pos = device_id.find(':');
   if (sep_pos == std::string::npos) {
     return NULL;
   }
   const base::StringPiece component1(device_id.data(), sep_pos);
   const base::StringPiece component2(device_id.data() + sep_pos + 1,
                                      device_id.length() - sep_pos - 1);
   int render_process_id = -1;
   int render_view_id = -1;
@@ skipping 41 matching lines @@
   capturer_->SetConsumer(NULL);
   capturer_->DeAllocate();
 }
 
 const media::VideoCaptureDevice::Name&
 WebContentsVideoCaptureDevice::device_name() {
   return device_name_;
 }
 
 }  // namespace content