Never lock the Pepper proxy lock on the IO thread

ppapi/shared_impl/proxy_lock.h

Index: ppapi/shared_impl/proxy_lock.h
diff --git a/ppapi/shared_impl/proxy_lock.h b/ppapi/shared_impl/proxy_lock.h
index 39b653e1a00bccb49217f9b494d4d5a666d5a67d..7fcf2cf23b2958f661fd8748b57c3a1806cc26f3 100644
--- a/ppapi/shared_impl/proxy_lock.h
+++ b/ppapi/shared_impl/proxy_lock.h
@@ -175,9 +175,6 @@ class RunWhileLockedHelper<void()> {
   typedef base::Callback<void()> CallbackType;
   explicit RunWhileLockedHelper(const CallbackType& callback)
       : callback_(new CallbackType(callback)) {
-    // Copying |callback| may adjust reference counts for bound Vars or
-    // Resources; we should have the lock already.
-    ProxyLock::AssertAcquired();

[dmichael (off chromium), 2015/03/24 20:10:26]

I needed to be able to use RunWhileLocked on the IO thread without the
ProxyLock, and I realized that for a while now, VarTracker and ResourceTracker
do their own checking, so we should be protected from mistakes like binding a
ScopedPPVar without the ProxyLock...
https://code.google.com/p/chromium/codesearch#chromium/src/ppapi/shared_impl/...
https://code.google.com/p/chromium/codesearch#chromium/src/ppapi/shared_impl/...

[raymes, 2015/03/25 01:43:59]

Is the name a bit misleading now then? Should we rename the function?

[dmichael (off chromium), 2015/03/25 17:35:04]

The name never really was meant to relate to whether the lock is held at the
time "RunWhileLocked" is invoked. The goal is to return a bound callback that
will run with the lock, so call sites look fairly self-explanatory like:
PostTask(FROM_HERE, RunWhileLocked(base::Bind(Foo::DoStuff)));

Arguably the name has always been misleading (maybe should be something like
BindWithProxyLock), but it looks pretty good at call-sites.

Anywho...  You're right, it doesn't belong in this CL so I moved to the other
one for TrackedCallback. If you still want a name change, you can comment there:
https://codereview.chromium.org/923263003/
...and I'd probably do that as a separate CL:

[raymes, 2015/03/26 06:30:51]

Ahh that makes complete sense then. No please keep the name as-is especially if
it makes sense from the call sites.

     // CallWhileLocked and destruction might happen on a different thread from
     // creation.
     thread_checker_.DetachFromThread();
@@ -268,7 +265,6 @@ class RunWhileLockedHelper<void(P1, P2)> {
   typedef base::Callback<void(P1, P2)> CallbackType;
   explicit RunWhileLockedHelper(const CallbackType& callback)
       : callback_(new CallbackType(callback)) {
-    ProxyLock::AssertAcquired();
     thread_checker_.DetachFromThread();
   }
   void CallWhileLocked(P1 p1, P2 p2) {
@@ -298,7 +294,6 @@ class RunWhileLockedHelper<void(P1, P2, P3)> {
   typedef base::Callback<void(P1, P2, P3)> CallbackType;
   explicit RunWhileLockedHelper(const CallbackType& callback)
       : callback_(new CallbackType(callback)) {
-    ProxyLock::AssertAcquired();
     thread_checker_.DetachFromThread();
   }
   void CallWhileLocked(P1 p1, P2 p2, P3 p3) {