Add content_browsertests for testing cache control flags

third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp

Index: third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
diff --git a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
index 7989e4075e9232c8b875e7a2932a71b645731d05..f65cbdef1a1c7b792238964cba956ebfc1232456 100644
--- a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
+++ b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
@@ -544,11 +544,6 @@ void ResourceFetcher::initializeRevalidation(const FetchRequest& request, Resour
 
     const AtomicString& lastModified = resource->response().httpHeaderField(HTTPNames::Last_Modified);
     const AtomicString& eTag = resource->response().httpHeaderField(HTTPNames::ETag);
-    if (!lastModified.isEmpty() || !eTag.isEmpty()) {
-        ASSERT(context().getCachePolicy() != CachePolicyReload);
-        if (context().getCachePolicy() == CachePolicyRevalidate)

[kinuko, 2016/05/12 08:45:05]

Hmm, it looks what we're changing here and the tests being added are not really
connected...

with the added tests I can see that calling
NavigationController::ReloadBypassingCache() sets cache control field but we
can't verify having CachePolicyRevalidate let the browser call
ReloadBypassingCache.

[Takashi Toyoshima, 2016/05/13 05:27:13]

I conformed that this code path is used for the image reload in the NormalReload
test.

What I did:
 - Re-add this deleted code path, and change line 550 not to add Cache-Control
header, but add "x-foo: bar".
 - Check if x-foo" can be found in the browser tests
 - See the header on the second empty16x16.png load in the NormalReload test

-            revalidatingRequest.setHTTPHeaderField(HTTPNames::Cache_Control, "max-age=0");
-    }
     if (!lastModified.isEmpty())
         revalidatingRequest.setHTTPHeaderField(HTTPNames::If_Modified_Since, lastModified);
     if (!eTag.isEmpty())