Support earliest seekable time in WMPI.

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 5be9452d38f572d1cd0acb5b9da0f1a7499771ce..e10420a9cc3da976cb6a393836d9f02c55c6d50f 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -488,6 +488,10 @@ bool WebMediaPlayerImpl::seeking() const {
   return seeking_;
 }
 
+double WebMediaPlayerImpl::earliestTime() const {
+  return pipeline_.GetMediaStartTime().InSecondsF();
+}
+
 double WebMediaPlayerImpl::duration() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
@@ -556,6 +560,7 @@ blink::WebTimeRanges WebMediaPlayerImpl::seekable() const {
   if (ready_state_ < WebMediaPlayer::ReadyStateHaveMetadata)
     return blink::WebTimeRanges();
 
+  const double seekable_start = pipeline_.GetMediaStartTime().InSecondsF();
   const double seekable_end = duration();
 
   // Allow a special exception for seeks to zero for streaming sources with a
@@ -567,7 +572,8 @@ blink::WebTimeRanges WebMediaPlayerImpl::seekable() const {
   // infinite duration so long as DataSource::IsStreaming() is false.  While not
   // expected, disabling this breaks semi-live players, http://crbug.com/427412.
   const blink::WebTimeRange seekable_range(
-      0.0, allow_seek_to_zero ? 0.0 : seekable_end);
+      allow_seek_to_zero ? 0.0 : seekable_start,
+      allow_seek_to_zero ? 0.0 : seekable_end);
   return blink::WebTimeRanges(&seekable_range, 1);
 }