Fix NULL pointers to rwlocks in WebRTC

patches/third_party/webrtc/002-webrtc-desktop_capturer_mac.patch

@@ -1,5 +1,5 @@
 diff --git a/modules/desktop_capture/screen_capturer_mac.mm b/modules/desktop_capture/screen_capturer_mac.mm
-index 78d977b47..306b3e6d9 100644
+index 9481f2a29..baf22f267 100644
 --- a/modules/desktop_capture/screen_capturer_mac.mm
 +++ b/modules/desktop_capture/screen_capturer_mac.mm
 @@ -37,6 +37,7 @@
@@ -10,7 +10,7 @@ index 78d977b47..306b3e6d9 100644
  
  // Once Chrome no longer supports OSX 10.8, everything within this
  // preprocessor block can be removed. https://crbug.com/579255
-@@ -70,20 +71,33 @@ namespace {
+@@ -70,20 +71,33 @@
  // destroy itself once it's done.
  class DisplayStreamManager {
   public:
@@ -52,7 +52,7 @@ index 78d977b47..306b3e6d9 100644
      RTC_CHECK(unique_id <= unique_id_generator_);
      DisplayStreamWrapper wrapper;
      wrapper.stream = stream;
-@@ -91,6 +105,7 @@ class DisplayStreamManager {
+@@ -91,6 +105,7 @@ void SaveStream(int unique_id,
    }
  
    void UnregisterActiveStreams() {
@@ -60,7 +60,7 @@ index 78d977b47..306b3e6d9 100644
      for (auto& pair : display_stream_wrappers_) {
        DisplayStreamWrapper& wrapper = pair.second;
        if (wrapper.active) {
-@@ -105,15 +120,23 @@ class DisplayStreamManager {
+@@ -105,15 +120,23 @@ void UnregisterActiveStreams() {
    }
  
    void PrepareForSelfDestruction() {
@@ -88,7 +88,7 @@ index 78d977b47..306b3e6d9 100644
  
   private:
    struct DisplayStreamWrapper {
-@@ -128,6 +151,7 @@ class DisplayStreamManager {
+@@ -128,6 +151,7 @@ void PrepareForSelfDestruction() {
    std::map<int, DisplayStreamWrapper> display_stream_wrappers_;
    int unique_id_generator_ = 0;
    bool ready_for_self_destruction_ = false;
@@ -96,7 +96,7 @@ index 78d977b47..306b3e6d9 100644
  };
  
  // Definitions used to dynamic-link to deprecated OS 10.6 functions.
-@@ -950,9 +974,6 @@ bool ScreenCapturerMac::RegisterRefreshAndMoveHandlers() {
+@@ -950,9 +974,6 @@ void ScreenRefresh(CGRectCount count,
              return;
            }
  
@@ -106,17 +106,17 @@ index 78d977b47..306b3e6d9 100644
            // Only pay attention to frame updates.
            if (status != kCGDisplayStreamFrameStatusFrameComplete)
              return;
-@@ -963,7 +984,12 @@ bool ScreenCapturerMac::RegisterRefreshAndMoveHandlers() {
+@@ -963,7 +984,12 @@ void ScreenRefresh(CGRectCount count,
            if (count != 0) {
              // According to CGDisplayStream.h, it's safe to call
              // CGDisplayStreamStop() from within the callback.
 -            ScreenRefresh(count, rects, display_origin);
-+	    manager->ReaderLock();
-+	    bool screen_capturer_mac_invalidated = manager->ShouldIgnoreUpdates();
-+	    if (!screen_capturer_mac_invalidated) {
++            manager->ReaderLock();
++            bool screen_capturer_mac_invalidated = manager->ShouldIgnoreUpdates();
++            if (!screen_capturer_mac_invalidated) {
 +              ScreenRefresh(count, rects, display_origin);
-+	    }
-+	    manager->ReaderUnlock();
++            }
++            manager->ReaderUnlock();
            }
          };
-     CGDisplayStreamRef display_stream = CGDisplayStreamCreate(
+ 

patches/third_party/webrtc/003-webrtc-rwlock_null.patch

@@ -0,0 +1,37 @@
+diff --git a/system_wrappers/source/rw_lock.cc b/system_wrappers/source/rw_lock.cc
+index ff53e8d7a..8c1156b65 100644
+--- a/system_wrappers/source/rw_lock.cc
++++ b/system_wrappers/source/rw_lock.cc
+@@ -9,8 +9,10 @@
+  */
+ 
+ #include "webrtc/system_wrappers/include/rw_lock_wrapper.h"
++#include "webrtc/system_wrappers/include/sleep.h"
+ 
+ #include <assert.h>
++#include <stdlib.h>
+ 
+ #if defined(_WIN32)
+ #include "webrtc/system_wrappers/source/rw_lock_win.h"
+@@ -21,11 +23,19 @@
+ namespace webrtc {
+ 
+ RWLockWrapper* RWLockWrapper::CreateRWLock() {
++  RWLockWrapper* rw_lock_ptr;
+ #ifdef _WIN32
+-  return RWLockWin::Create();
++  rw_lock_ptr = RWLockWin::Create();
+ #else
+-  return RWLockPosix::Create();
++  rw_lock_ptr = RWLockPosix::Create();
+ #endif
++  if (rw_lock_ptr != NULL) {
++    return rw_lock_ptr;
++  } else {
++    int msec_wait = 10 + (rand() % 90);
++    SleepMs(msec_wait);
++    return CreateRWLock();
++  }
+ }
+ 
+ }  // namespace webrtc