Fix crash caused by concurrent access to framebuffer_combo_complete_map_.

android_webview/browser/deferred_gpu_command_service.cc

Index: android_webview/browser/deferred_gpu_command_service.cc
diff --git a/android_webview/browser/deferred_gpu_command_service.cc b/android_webview/browser/deferred_gpu_command_service.cc
index 8e0591e656164367bbdafb76f037e000b9ac0cc3..30912872d877a83d7212d079f9ae528aeeb86691 100644
--- a/android_webview/browser/deferred_gpu_command_service.cc
+++ b/android_webview/browser/deferred_gpu_command_service.cc
@@ -10,6 +10,7 @@
 #include "base/synchronization/lock.h"
 #include "base/trace_event/trace_event.h"
 #include "content/public/browser/android/synchronous_compositor.h"
+#include "gpu/command_buffer/service/framebuffer_completeness_cache.h"
 #include "gpu/command_buffer/service/shader_translator_cache.h"
 #include "gpu/command_buffer/service/sync_point_manager.h"
 
@@ -153,6 +154,14 @@ DeferredGpuCommandService::shader_translator_cache() {
   return shader_translator_cache_;
 }
 
+scoped_refptr<gpu::gles2::FramebufferCompletenessCache>
+DeferredGpuCommandService::framebuffer_completeness_cache() {
+  if (!framebuffer_completeness_cache_.get())
+    framebuffer_completeness_cache_ =
+        new gpu::gles2::FramebufferCompletenessCache;
+  return framebuffer_completeness_cache_;
+}
+
 gpu::SyncPointManager* DeferredGpuCommandService::sync_point_manager() {
   return sync_point_manager_.get();
 }