Bug 1260599 - Enable EXT_disjoint_timer_query extension on ANGLE. r=jgilbert

--HG--
extra : rebase_source : cd31f7ff2daa4fec743726fd2e1a04ca83820b5b

dom/canvas/WebGLContext.cpp

@@ -1630,6 +1630,13 @@ WebGLContext::DummyReadFramebufferOperation(const char* funcName)
     }
 }
 
+bool
+WebGLContext::HasTimestampBits() const
+{
+    // 'sync' provides glGetInteger64v either by supporting ARB_sync, GL3+, or GLES3+.
+    return gl->IsSupported(GLFeature::sync);
+}
+
 static bool
 CheckContextLost(GLContext* gl, bool* const out_isGuilty)
 {

dom/canvas/WebGLContext.h

@@ -1475,6 +1475,8 @@ protected:
     bool mNeedsFakeNoStencil;
     bool mNeedsEmulatedLoneDepthStencil;
 
+    bool HasTimestampBits() const;
+
     struct ScopedMaskWorkaround {
         WebGLContext& mWebGL;
         const bool mFakeNoAlpha;

dom/canvas/WebGLContextState.cpp

@@ -267,7 +267,11 @@ WebGLContext::GetParameter(JSContext* cx, GLenum pname, ErrorResult& rv)
     if (IsWebGL2() || IsExtensionEnabled(WebGLExtensionID::EXT_disjoint_timer_query)) {
         if (pname == LOCAL_GL_TIMESTAMP_EXT) {
             GLuint64 iv = 0;
-            gl->fGetInteger64v(pname, (GLint64*) &iv);
+            if (HasTimestampBits()) {
+                gl->fGetInteger64v(pname, (GLint64*)&iv);
+            } else {
+                GenerateWarning("QUERY_COUNTER_BITS_EXT for TIMESTAMP_EXT is 0.");
+            }
             // TODO: JS doesn't support 64-bit integers. Be lossy and
             // cast to double (53 bits)
             return JS::NumberValue(static_cast<double>(iv));

dom/canvas/WebGLExtensionDisjointTimerQuery.cpp

@@ -177,7 +177,9 @@ WebGLExtensionDisjointTimerQuery::GetQueryEXT(JSContext* cx, GLenum target,
       return;
     }
     GLint bits = 0;
-    mContext->GL()->fGetQueryiv(target, pname, &bits);
+    if (mContext->HasTimestampBits()) {
+      mContext->GL()->fGetQueryiv(target, pname, &bits);
+    }
     retval.set(JS::Int32Value(int32_t(bits)));
     break;
   }
@@ -242,11 +244,7 @@ WebGLExtensionDisjointTimerQuery::IsSupported(const WebGLContext* webgl)
   gl::GLContext* gl = webgl->GL();
   return gl->IsSupported(gl::GLFeature::query_objects) &&
          gl->IsSupported(gl::GLFeature::get_query_object_i64v) &&
-         gl->IsSupported(gl::GLFeature::query_counter) && // provides GL_TIMESTAMP
-         gl->IsSupported(gl::GLFeature::sync); // provides glGetInteger64v
-  // 'sync' provides glGetInteger64v either by supporting ARB_sync, GL3+, or GLES3+.
-  // Since there are no differences between support for glGetInteger64v and support for
-  // 'sync', we just piggy-back off of 'sync'.
+         gl->IsSupported(gl::GLFeature::query_counter); // provides GL_TIMESTAMP
 }
 
 void