[customtabs] Increase max response size of DetachedResourceRequest.

Some misconfigured servers redirect to a 200 code instead of a 204,
meaning that the response payload can be quite large. This is not an
issue in practice, but it does confuse metrics a bit. Since there is no
harm in increasing the limit, do it to make metrics easier to
understand.

Bug: 816837
Change-Id: I908a3cad22779b57bdb78f5957e8839048ee3597
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339981Reviewed-by: Peter Conn <peconn@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795533}

chrome/browser/android/customtabs/detached_resource_request.h

@@ -39,7 +39,7 @@ namespace customtabs {
 // This is a UI thread class.
 class DetachedResourceRequest {
  public:
-  static constexpr int kMaxResponseSize = 100 * 1024;
+  static constexpr int kMaxResponseSize = 500 * 1024;
 
   // The motivation of the resource request, used for histograms reporting.
   // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser.customtabs

chrome/browser/android/customtabs/detached_resource_request_unittest.cc

@@ -143,9 +143,8 @@ std::unique_ptr<HttpResponse> LargeHeadersAndResponseSize(
     return nullptr;
 
   auto response = std::make_unique<net::test_server::BasicHttpResponse>();
-  response->AddCustomHeader(
-      "X-Large-Header",
-      std::string(DetachedResourceRequest::kMaxResponseSize, 'b'));
+  // Maximum header size ios 256kB, stay below it.
+  response->AddCustomHeader("X-Large-Header", std::string(100 * 1024, 'b'));
   response->set_code(net::HTTP_OK);
 
   uint32_t length;
@@ -163,9 +162,8 @@ std::unique_ptr<HttpResponse> LargeResponseAndCookie(
 
   auto response = std::make_unique<net::test_server::BasicHttpResponse>();
   response->AddCustomHeader("Set-Cookie", kCookieFromLargeResponse);
-  response->AddCustomHeader(
-      "X-Large-Header",
-      std::string(DetachedResourceRequest::kMaxResponseSize, 'b'));
+  // Maximum header size ios 256kB, stay below it.
+  response->AddCustomHeader("X-Large-Header", std::string(100 * 1024, 'b'));
   response->set_code(net::HTTP_OK);
   response->set_content(
       std::string(DetachedResourceRequest::kMaxResponseSize + 1, 'a'));