media: Allow suspend on HTTP 200 videos

Currently, connections are kept open indefinitely, which
can block future loads from a server if there are 6 or more
<video> tags on the same page.  This should fix that in most
cases.

BUG=716748

Review-Url: https://codereview.chromium.org/2979893002
Cr-Commit-Position: refs/heads/master@{#486919}

media/blink/multibuffer_data_source_unittest.cc

@@ -601,14 +601,15 @@ TEST_F(MultibufferDataSourceTest, Range_WrongContentRange) {
 TEST_F(MultibufferDataSourceTest, Range_ServerLied) {
   InitializeWith206Response();
 
-  // Read causing a new request to be made -- we'll expect it to error.
+  // Read causing a new request to be made, we will discard the data that
+  // was already read in the first request.
   ReadAt(kFarReadPosition);
 
   // Return a 200 in response to a range request.
   EXPECT_CALL(*this, ReadCallback(media::DataSource::kReadError));
   Respond(response_generator_->Generate200());
 
-  EXPECT_FALSE(loading());
+  EXPECT_TRUE(loading());
   Stop();
 }
 

media/blink/resource_multibuffer_data_provider.cc

@@ -287,6 +287,7 @@ void ResourceMultiBufferDataProvider::DidReceiveResponse(
   int64_t content_length = response.ExpectedContentLength();
   bool end_of_file = false;
   bool do_fail = false;
+  bytes_to_discard_ = 0;
 
   // We make a strong assumption that when we reach here we have either
   // received a response from HTTP/HTTPS protocol or the request was
@@ -308,11 +309,12 @@ void ResourceMultiBufferDataProvider::DidReceiveResponse(
     if (partial_response &&
         VerifyPartialResponse(response, destination_url_data)) {
       destination_url_data->set_range_supported();
-    } else if (ok_response && pos_ == 0) {
+    } else if (ok_response) {
       // We accept a 200 response for a Range:0- request, trusting the
       // Accept-Ranges header, because Apache thinks that's a reasonable thing
       // to return.
       destination_url_data->set_length(content_length);
+      bytes_to_discard_ = byte_pos();
     } else if (response.HttpStatusCode() == kHttpRangeNotSatisfiable) {
       // Unsatisfiable range
       // Really, we should never request a range that doesn't exist, but
@@ -386,6 +388,15 @@ void ResourceMultiBufferDataProvider::DidReceiveData(const char* data,
   DCHECK(active_loader_);
   DCHECK_GT(data_length, 0);
 
+  if (bytes_to_discard_) {
+    uint64_t tmp = std::min<uint64_t>(bytes_to_discard_, data_length);
+    data_length -= tmp;
+    data += tmp;
+    bytes_to_discard_ -= tmp;
+    if (data_length == 0)
+      return;
+  }
+
   // When we receive data, we allow more retries.
   retries_ = 0;
 
@@ -561,9 +572,13 @@ bool ResourceMultiBufferDataProvider::VerifyPartialResponse(
     url_data->set_length(instance_size);
   }
 
-  if (byte_pos() != first_byte_position) {
+  if (first_byte_position > byte_pos()) {
+    return false;
+  }
+  if (last_byte_position + 1 < byte_pos()) {
     return false;
   }
+  bytes_to_discard_ = byte_pos() - first_byte_position;
 
   return true;
 }

media/blink/resource_multibuffer_data_provider.h

@@ -119,6 +119,10 @@ class MEDIA_BLINK_EXPORT ResourceMultiBufferDataProvider
   // When we encounter a redirect, this is the source of the redirect.
   GURL redirects_to_;
 
+  // If the server tries to gives us more bytes than we want, this how
+  // many bytes we need to discard before we get to the right place.
+  uint64_t bytes_to_discard_ = 0;
+
   base::WeakPtrFactory<ResourceMultiBufferDataProvider> weak_factory_;
 };
 

media/blink/webmediaplayer_impl.cc

@@ -1820,6 +1820,11 @@ void WebMediaPlayerImpl::DataSourceInitialized(bool success) {
     return;
   }
 
+  // No point in preloading data as we'll probably just throw it away anyways.
+  if (IsStreaming() && preload_ > MultibufferDataSource::METADATA) {
+    data_source_->SetPreload(MultibufferDataSource::METADATA);
+  }
+
   StartPipeline();
 }
 
@@ -2100,7 +2105,18 @@ void WebMediaPlayerImpl::UpdatePlayState() {
   bool can_auto_suspend = true;
 #else
   bool is_remote = false;
-  bool can_auto_suspend = !disable_pipeline_auto_suspend_ && !IsStreaming();
+  bool can_auto_suspend = !disable_pipeline_auto_suspend_;
+  // For streaming videos, we only allow suspending at the very beginning of the
+  // video, and only if we know the length of the video. (If we don't know
+  // the length, it might be a dynamically generated video, and suspending
+  // will not work at all.)
+  if (IsStreaming()) {
+    bool at_beginning =
+        ready_state_ == WebMediaPlayer::kReadyStateHaveNothing ||
+        CurrentTime() == 0.0;
+    if (!at_beginning || GetPipelineMediaDuration() == kInfiniteDuration)
+      can_auto_suspend = false;
+  }
 #endif
 
   bool is_suspended = pipeline_controller_.IsSuspended();

third_party/WebKit/LayoutTests/http/tests/media/gc-while-network-loading.html

@@ -11,7 +11,7 @@ async_test(function(t)
     var mediaFile = findMediaFile("video", "../../../media/content/test");
     var type = mimeTypeForExtension(mediaFile.split(".").pop());
     v.src = "http://127.0.0.1:8000/media/video-throttled-load.cgi?name=" + mediaFile + "&throttle=50&type=" + type;
-    v.onloadeddata = t.step_func(function()
+    v.onloadstart = t.step_func(function()
     {
         assert_equals(v.networkState, v.NETWORK_LOADING);
         // The delaying-the-load-event flag is now false.