Remove several calls to Page::mainFrame

Source/core/inspector/InspectorDatabaseAgent.cpp

Index: Source/core/inspector/InspectorDatabaseAgent.cpp
diff --git a/Source/core/inspector/InspectorDatabaseAgent.cpp b/Source/core/inspector/InspectorDatabaseAgent.cpp
index 095c010e1b27f95da34e1d2800ad292b0dee35ea..11960dfe0cf668e8b47c548b5725750c35cff6d4 100644
--- a/Source/core/inspector/InspectorDatabaseAgent.cpp
+++ b/Source/core/inspector/InspectorDatabaseAgent.cpp
@@ -208,6 +208,9 @@ void InspectorDatabaseAgent::didOpenDatabase(PassRefPtr<Database> database, cons
 
 void InspectorDatabaseAgent::didCommitLoad(Frame* frame, DocumentLoader* loader)
 {
+    // FIXME: If "frame" is always guarenteed to be in the same Page as loader->frame()
+    // then all we need to check here is loader->frame()->isMainFrame()
+    // and we don't need "frame" at all.
     if (loader->frame() != frame->page()->mainFrame())
         return;