Pass context capabilities via cc::ContextProvider instead of gl string

This migrates cc to checking for context capabilities through a struct
provided by the ContextProvider instead of parsing out the GL_EXTENSIONS
string manually. This is a very minor performance win, since we don't
parse the string multiple times. More importantly, this centralizes
capability testing into one place and breaks cc's dependency on
WebString.

The implementation of ContextCapabilities() in content still parses out
the extensions string from the context, but we can route this data in
more directly in a follow-up.

BUG=279518

Review URL: https://chromiumcodereview.appspot.com/23466003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@220186 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 23 insertions, 0 deletions

diff --git a/cc/output/context_provider.h b/cc/output/context_provider.h
index 7d61763..3aae7eb 100644
--- a/cc/output/context_provider.h
+++ b/cc/output/context_provider.h
@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
+#include "cc/base/cc_export.h"
 
 class GrContext;
 namespace WebKit { class WebGraphicsContext3D; }
@@ -25,6 +26,28 @@ class ContextProvider : public base::RefCountedThreadSafe<ContextProvider> {
   virtual WebKit::WebGraphicsContext3D* Context3d() = 0;
   virtual class GrContext* GrContext() = 0;
 
+  struct Capabilities {
+    bool bind_uniform_location;
+    bool discard_backbuffer;
+    bool egl_image_external;
+    bool fast_npot_mo8_textures;
+    bool iosurface;
+    bool map_image;
+    bool map_sub;
+    bool post_sub_buffer;
+    bool set_visibility;
+    bool shallow_flush;
+    bool swapbuffers_complete_callback;
+    bool texture_format_bgra8888;
+    bool texture_rectangle;
+    bool texture_storage;
+    bool texture_usage;
+
+    CC_EXPORT Capabilities();
+  };
+  // Returns the capabilities of the currently bound 3d context.
+  virtual Capabilities ContextCapabilities() = 0;
+
   // Ask the provider to check if the contexts are valid or lost. If they are,
   // this should invalidate the provider so that it can be replaced with a new
   // one.