media: Use GL shared worker context instead of allocating one.

Media used to create its own GL context. This context, that takes up a
few MBs of memory, was used to create textures, mailboxes and syncpoints.

This CL replaces the media context with the shared worker context already
present in RenderThreadImpl. It also makes sure that media drops any reference
to it in the main thread (that's required by the shared worker context.)

This change will also allow media to access the context in a worker thread,
in this way the GL operations won't need to be serialized on the media thread
that might be busy decoding video/audio.

NOTE: media didn't handle GL context lost properly, but simply stopped working
after the first context lost. This CL doesn't fix that and reproduces the same
behavior.

BUG=544547
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1369843002

Cr-Commit-Position: refs/heads/master@{#354848}

1 files changed, 6 insertions, 2 deletions

diff --git a/content/common/gpu/client/command_buffer_proxy_impl.cc b/content/common/gpu/client/command_buffer_proxy_impl.cc
index 9bd4471..b5f9a36b 100644
--- a/content/common/gpu/client/command_buffer_proxy_impl.cc
+++ b/content/common/gpu/client/command_buffer_proxy_impl.cc
@@ -131,13 +131,17 @@ void CommandBufferProxyImpl::OnConsoleMessage(
 }
 
 void CommandBufferProxyImpl::AddDeletionObserver(DeletionObserver* observer) {
-  CheckLock();
+  scoped_ptr<base::AutoLock> lock;
+  if (lock_)
+    lock.reset(new base::AutoLock(*lock_));
   deletion_observers_.AddObserver(observer);
 }
 
 void CommandBufferProxyImpl::RemoveDeletionObserver(
     DeletionObserver* observer) {
-  CheckLock();
+  scoped_ptr<base::AutoLock> lock;
+  if (lock_)
+    lock.reset(new base::AutoLock(*lock_));
   deletion_observers_.RemoveObserver(observer);
 }