[Android cast] Make the local player exit seeking mode on cast start

chrome/android/java/src/org/chromium/chrome/browser/media/remote/DefaultMediaRouteController.java

Index: chrome/android/java/src/org/chromium/chrome/browser/media/remote/DefaultMediaRouteController.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/remote/DefaultMediaRouteController.java b/chrome/android/java/src/org/chromium/chrome/browser/media/remote/DefaultMediaRouteController.java
index 619cd7763608805f3740005551a0438e48367dfb..a86920d83979f3651d6f1ea84fa0e40b82515eba 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/media/remote/DefaultMediaRouteController.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/remote/DefaultMediaRouteController.java
@@ -774,6 +774,7 @@ protected void clearStreamState() {
         mVideoUriToStart = null;
         mLocalVideoUri = null;
         mCurrentSessionId = null;
+        mLastKnownStreamPosition = 0;

[dgn, 2016/01/12 14:36:26]

mLastKnownStreamPosition to be reset, upon starting a new stream, otherwise that
position is sent back to the local player. The local player has code that makes
sure the position doesn't jump back while playing (see
https://codereview.chromium.org/1313613003) so it makes it be out of sync if a
seek backwards is made before casting.

[aberent, 2016/01/12 15:54:56]

I thought we wanted the position sent back to the local player. We want it to
continue from the position where casting stopped. Have a look at
onRouteUnselectedEvent, which sets mLastKnownStreamPosition immediately before
calling clearStreamState. This will cancel that, so at least one of them must be
wrong.

[dgn, 2016/01/13 12:25:54]

Thanks I missed that it was called on disconnect too. Moved to be called only
when starting to cast out of reconnect contexts

         clearItemState();
 
         if (getContext() != null) {