Handle compressed textures allocated via TexStorage2D.

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
index 78c2559925e0c2cfe58f10f03c33338a4d299438..0b1561c24157fc57e00cb9b0d8ae3a089bcf7168 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp
@@ -780,7 +780,8 @@ bool WebGL2RenderingContextBase::validateTexStorage(const char* functionName, GL
         return false;
     }
 
-    if (m_supportedInternalFormatsStorage.find(internalformat) == m_supportedInternalFormatsStorage.end()) {
+    if (m_supportedInternalFormatsStorage.find(internalformat) == m_supportedInternalFormatsStorage.end()
+        && (functionType == TexStorageType2D && !m_compressedTextureFormats.contains(internalformat))) {
         synthesizeGLError(GL_INVALID_ENUM, functionName, "invalid internalformat");
         return false;
     }