android: Implement single origin and CORS check for video

webkit/media/android/media_info_loader_android.cc

+// Copyright (c) 2013 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 "webkit/media/android/media_info_loader_android.h"
+
+#include "base/bits.h"
+#include "base/callback_helpers.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebURLError.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebURLLoader.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebURLResponse.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
+
+using WebKit::WebFrame;
+using WebKit::WebURLError;
+using WebKit::WebURLLoader;
+using WebKit::WebURLLoaderOptions;
+using WebKit::WebURLRequest;
+using WebKit::WebURLResponse;
+
+namespace webkit_media {
+
+static const int kHttpOK = 200;
+
+MediaInfoLoaderAndroid::MediaInfoLoaderAndroid(
+    const GURL& url,
+    WebKit::WebMediaPlayer::CORSMode cors_mode,
+    const ReadyCB& ready_cb)
+    : loader_failed_(false),
+      url_(url),
+      cors_mode_(cors_mode),
+      single_origin_(true),
+      ready_cb_(ready_cb) {}
+
+MediaInfoLoaderAndroid::~MediaInfoLoaderAndroid() {
+  ready_cb_.Reset();
+  active_loader_.reset();
+}
+
+void MediaInfoLoaderAndroid::Start(WebKit::WebFrame* frame) {
+  // Make sure we have not started.
+  DCHECK(!ready_cb_.is_null());
+  CHECK(frame);
+
+  // Prepare the request.
+  WebURLRequest request(url_);
+  request.setTargetType(WebURLRequest::TargetIsMedia);
+  frame->setReferrerForRequest(request, WebKit::WebURL());
+
+  scoped_ptr<WebURLLoader> loader;
+  if (test_loader_) {
+    loader = test_loader_.Pass();
+  } else {
+    WebURLLoaderOptions options;
+    if (cors_mode_ == WebKit::WebMediaPlayer::CORSModeUnspecified) {
+      options.allowCredentials = true;
+      options.crossOriginRequestPolicy =
+          WebURLLoaderOptions::CrossOriginRequestPolicyAllow;
+    } else {
+      options.exposeAllResponseHeaders = true;
+      options.crossOriginRequestPolicy =
+          WebURLLoaderOptions::CrossOriginRequestPolicyUseAccessControl;
+      if (cors_mode_ == WebKit::WebMediaPlayer::CORSModeUseCredentials)
+        options.allowCredentials = true;
+    }
+    loader.reset(frame->createAssociatedURLLoader(options));
+  }
+
+  // Start the resource loading.
+  loader->loadAsynchronously(request, this);
+  active_loader_.reset(new ActiveLoader(loader.Pass()));
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// WebKit::WebURLLoaderClient implementation.
+void MediaInfoLoaderAndroid::willSendRequest(
+    WebURLLoader* loader,
+    WebURLRequest& newRequest,
+    const WebURLResponse& redirectResponse) {
+
+  // The load may have been stopped and |ready_cb| is destroyed.
+  // In this case we shouldn't do anything.
+  if (ready_cb_.is_null()) {
+    // Set the url in the request to an invalid value (empty url).
+    newRequest.setURL(WebKit::WebURL());
+    return;
+  }
+
+  // Only allow |single_origin_| if we haven't seen a different origin yet.
+  if (single_origin_)
+    single_origin_ = url_.GetOrigin() == GURL(newRequest.url()).GetOrigin();
+
+  url_ = newRequest.url();
+}
+
+void MediaInfoLoaderAndroid::didSendData(
+    WebURLLoader* loader,
+    unsigned long long bytes_sent,
+    unsigned long long total_bytes_to_be_sent) {
+  NOTIMPLEMENTED();
+}
+
+void MediaInfoLoaderAndroid::didReceiveResponse(
+    WebURLLoader* loader,
+    const WebURLResponse& response) {
+  DVLOG(1) << "didReceiveResponse: HTTP/"
+           << (response.httpVersion() == WebURLResponse::HTTP_0_9 ? "0.9" :
+               response.httpVersion() == WebURLResponse::HTTP_1_0 ? "1.0" :
+               response.httpVersion() == WebURLResponse::HTTP_1_1 ? "1.1" :
+               "Unknown")
+           << " " << response.httpStatusCode();
+  DCHECK(active_loader_.get());
+  if (response.httpStatusCode() == kHttpOK) {
+    DidBecomeReady(kOk);
+  } else {
+    loader_failed_ = true;
+    DidBecomeReady(kFailed);
+  }
+}
+
+void MediaInfoLoaderAndroid::didReceiveData(
+    WebURLLoader* loader,
+    const char* data,
+    int data_length,
+    int encoded_data_length) {
+  // Ignored.

[scherkus (not reviewing), 2013/06/03 16:57:04]

so if this was a 100MB media resource do we end up downloading the same file
twice using both Chrome's network stack and Android's media player stack?

[Sami, 2013/06/03 17:12:56]

No, because as soon as we get a response from the server we cancel the load --
see DidBecomeReady.

[scherkus (not reviewing), 2013/06/03 17:37:39]

OK .. but this is still an additional HTTP roundtrip that gets cancelled prior
to doing the real load, which is pretty unfortunate.

Do you have any #s on how this will affect load times over mobile networks?

Have you reached out to the Android team to see whether they can provide this
information in a future version of the API?

+}
+
+void MediaInfoLoaderAndroid::didDownloadData(
+    WebKit::WebURLLoader* loader,
+    int dataLength) {
+  NOTIMPLEMENTED();
+}
+
+void MediaInfoLoaderAndroid::didReceiveCachedMetadata(
+    WebURLLoader* loader,
+    const char* data,
+    int data_length) {
+  NOTIMPLEMENTED();
+}
+
+void MediaInfoLoaderAndroid::didFinishLoading(
+    WebURLLoader* loader,
+    double finishTime) {
+  DCHECK(active_loader_.get());
+  DidBecomeReady(kOk);
+}
+
+void MediaInfoLoaderAndroid::didFail(
+    WebURLLoader* loader,
+    const WebURLError& error) {
+  DVLOG(1) << "didFail: reason=" << error.reason
+           << ", isCancellation=" << error.isCancellation
+           << ", domain=" << error.domain.utf8().data()
+           << ", localizedDescription="
+           << error.localizedDescription.utf8().data();
+  DCHECK(active_loader_.get());
+  loader_failed_ = true;
+  DidBecomeReady(kFailed);
+}
+
+bool MediaInfoLoaderAndroid::HasSingleOrigin() const {
+  DCHECK(ready_cb_.is_null())
+      << "Must become ready before calling HasSingleOrigin()";
+  return single_origin_;
+}
+
+bool MediaInfoLoaderAndroid::DidPassCORSAccessCheck() const {
+  DCHECK(ready_cb_.is_null())
+      << "Must become ready before calling DidPassCORSAccessCheck()";
+  return !loader_failed_ &&
+      cors_mode_ != WebKit::WebMediaPlayer::CORSModeUnspecified;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// Helper methods.
+
+void MediaInfoLoaderAndroid::DidBecomeReady(Status status) {
+  active_loader_.reset();
+  if (!ready_cb_.is_null())
+    base::ResetAndReturn(&ready_cb_).Run(status);
+}
+
+}  // namespace webkit_media