[Origin Trials] Install origin trial bindings on V8 context conditionally
This patch removes the call-time check for origin-trial-enabled features,
replacing it with code that installs features into the V8 context as trial
tokens are encountered. This means that experimental features which were previously polluting the global namespaces are now completely unavailable except when enabled by origin trials. (The specific case of pollution caused by Durable Storage is removed from test expectations in this patch)
Origin trials are now initialized after the V8 context, by calling initializeOriginTrials. This calls, through a series of function pointers, the bindings initialization code for core, modules, and optionally internals (for tests).
This patch implements the design at https://docs.google.com/document/d/1vwKD8sUrr5mtktvEwvO_f2KUsNhpcgLMixYXhD8K4KY
BUG=584367
Review-Url: https://codereview.chromium.org/2005433002
Cr-Commit-Position: refs/heads/master@{#396860}
27 files changed
