Make ShaderTranslatorCache thread safe

android_webview/browser/hardware_renderer.cc

Index: android_webview/browser/hardware_renderer.cc
diff --git a/android_webview/browser/hardware_renderer.cc b/android_webview/browser/hardware_renderer.cc
index 8042d9d4fff60e94578bca99b34161592a3f8e04..59356dbe7aea8656256a2fcba77c99ddf9e09d4d 100644
--- a/android_webview/browser/hardware_renderer.cc
+++ b/android_webview/browser/hardware_renderer.cc
@@ -14,6 +14,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/content_switches.h"
+#include "gpu/command_buffer/service/shader_translator_cache.h"
 #include "ui/gfx/transform.h"
 
 using content::BrowserThread;
@@ -252,6 +253,13 @@ void DeferredGpuCommandService::ScheduleIdleWork(
 
 bool DeferredGpuCommandService::UseVirtualizedGLContexts() { return true; }
 
+scoped_refptr<gpu::gles2::ShaderTranslatorCache>
+DeferredGpuCommandService::shader_translator_cache() {
+  if (!shader_translator_cache_.get())
+    shader_translator_cache_ = new gpu::gles2::ShaderTranslatorCache;
+  return shader_translator_cache_;
+}
+
 void DeferredGpuCommandService::RunTasks() {
   bool has_more_tasks;
   {