ResourceFetcherTest: introduce FetchTestingPlatformSupport

third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp

Index: third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
diff --git a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
index bf236c696032c10c883a53b7973e868baaf71cb0..9fea2defa65799960987636f000ae7d732a869d3 100644
--- a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
+++ b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
@@ -34,6 +34,7 @@
 #include "base/memory/discardable_memory_allocator.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/statistics_recorder.h"
+#include "base/run_loop.h"
 #include "base/test/icu_test_util.h"
 #include "base/test/test_discardable_memory_allocator.h"
 #include "cc/blink/web_compositor_support_impl.h"
@@ -196,6 +197,10 @@ InterfaceProvider* TestingPlatformSupport::interfaceProvider() {
   return m_interfaceProvider.get();
 }
 
+void TestingPlatformSupport::runUntilIdle() {
+  base::RunLoop().RunUntilIdle();
+}
+
 // TestingPlatformSupportWithMockScheduler definition:
 
 TestingPlatformSupportWithMockScheduler::