Implementing preload=metadata for video

This patch implements the logic necessary to respect the preload attribute
when it is set to MetaData.  This also refactors the BufferedResourceLoader
to determine its buffering techniques based on a DeferStrategy value.

BUG=16482,76555
TEST=media/video-preload.html, test_shell_tests

Review URL: http://codereview.chromium.org/6625059

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@80465 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 17 insertions, 0 deletions

diff --git a/webkit/glue/media/buffered_data_source.h b/webkit/glue/media/buffered_data_source.h
index 2c9e904..933ffb9 100644
--- a/webkit/glue/media/buffered_data_source.h
+++ b/webkit/glue/media/buffered_data_source.h
@@ -11,6 +11,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "media/base/filter_factories.h"
+#include "media/base/filters.h"
 #include "webkit/glue/media/buffered_resource_loader.h"
 
 namespace webkit_glue {
@@ -40,6 +41,7 @@ class BufferedDataSource : public WebDataSource {
                     media::DataSource::ReadCallback* read_callback);
   virtual bool GetSize(int64* size_out);
   virtual bool IsStreaming();
+  virtual void SetPreload(media::Preload preload);
 
   const media::MediaFormat& media_format() {
     return media_format_;
@@ -90,6 +92,13 @@ class BufferedDataSource : public WebDataSource {
   // and signals the buffered resource loader accordingly.
   void SetPlaybackRateTask(float playback_rate);
 
+  // This task saves the preload value for the media.
+  void SetPreloadTask(media::Preload preload);
+
+  // Decides which DeferStrategy to used based on the current state of the
+  // BufferedDataSource.
+  BufferedResourceLoader::DeferStrategy ChooseDeferStrategy();
+
   // The method that performs actual read. This method can only be executed on
   // the render thread.
   void ReadInternal();
@@ -196,6 +205,14 @@ class BufferedDataSource : public WebDataSource {
   // are in a playing state.
   bool media_is_paused_;
 
+  // This variable is true when the user has requested the video to play at
+  // least once.
+  bool media_has_played_;
+
+  // This variable holds the value of the preload attribute for the video
+  // element.
+  media::Preload preload_;
+
   // This timer is to run the WatchDogTask repeatedly. We use a timer instead
   // of doing PostDelayedTask() reduce the extra reference held by the message
   // loop. The RepeatingTimer does PostDelayedTask() internally, by using it