Use HTTP response headers for PNaCl caching instead of bitcode hash.

Use Last-Modified and/or ETag values from the server plus
the bitcode URL as a cache key.  This allows us to remove
a hash from the bitcode header and/or the PNaCl manifests.
Also, start applying "Cache-Control: no-store" to the
translated nexe, if it is part of the pexe's GET response.

This also shifts around some of the file_downloader code
to allow us to get a callback after the initial GET request,
but before the streaming is completely done.

Some caveats due to the layering of the trusted NaCl plugin
vs the rest of chrome:

* We end up with a basic HTTP response parser that splits
fields based on what is returned by ppb_url_response_info.
This can have been replaced by net/http/http_response_info.h
For now, we end up with some extra testing burden.
See: nacl_http_response_headers_unittest.cc
Once we can depend on net/, we can replace this code.

* We end up with some key sanitization.  Until we
switch from the HTML5 Filesystem to our own cache backend
there are 2 or 3 characters that are disallowed
in filenames.
See: http://dev.w3.org/2009/dap/file-system/file-dir-sys.html#naming-restrictions
We did not run into that problem in the past because the
NMF file's hash only had hexadecimal characters,
which is okay.

* Since the URL is now part of the cache, and not some
hash of the contents, once the PNaCl cache is not
per-origin, we have to be a bit careful that a user can
only store something to its own origin.  Perhaps that
checking can be done with SiteInstance's IsSameWebsite()?


This replaces: https://codereview.chromium.org/14683004.
With no sha hash to read, there is sha hash to verify.


BUG=http://code.google.com/p/nativeclient/issues/detail?id=2992

TEST=ppapi_unittests --gtest_filter=NaClHttpResponseHeadersTest*

TEST=browser_tests --gtest_filter=*Pnacl*

Review URL: https://chromiumcodereview.appspot.com/16569002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@206797 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 13 insertions, 0 deletions

diff --git a/ppapi/cpp/completion_callback.h b/ppapi/cpp/completion_callback.h
index cdd8b06..14d6784 100644
--- a/ppapi/cpp/completion_callback.h
+++ b/ppapi/cpp/completion_callback.h
@@ -85,6 +85,19 @@ class CompletionCallback {
     PP_RunCompletionCallback(&cc_, result);
   }
 
+  /// RunAndClear() is used to run the <code>CompletionCallback</code> and
+  /// clear out the callback so that it cannot be run a second time.
+  ///
+  /// @param[in] result The result of the operation to be passed to the
+  /// callback function. Non-positive values correspond to the error codes
+  /// from <code>pp_errors.h</code> (excluding
+  /// <code>PP_OK_COMPLETIONPENDING</code>). Positive values indicate
+  /// additional information such as bytes read.
+  void RunAndClear(int32_t result) {
+    PP_DCHECK(cc_.func);
+    PP_RunAndClearCompletionCallback(&cc_, result);
+  }
+
   /// IsOptional() is used to determine the setting of the
   /// <code>PP_COMPLETIONCALLBACK_FLAG_OPTIONAL</code> flag. This flag allows
   /// any method taking such callback to complete synchronously