disable floating point textures if GLSL version is < 330

BUG=skia:

Review URL: https://codereview.chromium.org/1178723007
diff --git a/src/gpu/gl/GrGLContext.cpp b/src/gpu/gl/GrGLContext.cpp
index 6f23eca..adbc5d9 100644
--- a/src/gpu/gl/GrGLContext.cpp
+++ b/src/gpu/gl/GrGLContext.cpp
@@ -40,18 +40,20 @@
 
     args.fVendor = GrGLGetVendor(interface);
 
+    args.fRenderer = GrGLGetRendererFromString(renderer);
+
     /*
-     * Qualcomm drivers have a horrendous bug with some drivers. Though they claim to
-     * support GLES 3.00, some perfectly valid GLSL300 shaders will only compile with
+     * Qualcomm drivers for the 3xx series have a horrendous bug with some drivers. Though they
+     * claim to support GLES 3.00, some perfectly valid GLSL300 shaders will only compile with
      * #version 100, and will fail to compile with #version 300 es.  In the long term, we
      * need to lock this down to a specific driver version.
+     * ?????/2015 - This bug is still present in Lollipop pre-mr1
+     * 06/18/2015 - This bug does not affect the nexus 6 (which has an Adreno 4xx).
      */
-    if (kQualcomm_GrGLVendor == args.fVendor) {
+    if (kAdreno3xx_GrGLRenderer == args.fRenderer) {
         args.fGLSLGeneration = k110_GrGLSLGeneration;
     }
 
-    args.fRenderer = GrGLGetRendererFromString(renderer);
-
     GrGLGetDriverInfo(interface->fStandard, args.fVendor, renderer, ver,
                       &args.fDriver, &args.fDriverVersion);