Bug 715190 - Clear existing GL errors before trying to check for a new one r=clord

mobile/android/base/gfx/WidgetTileLayer.java

@@ -50,6 +50,7 @@ import javax.microedition.khronos.opengles.GL10;
  * Encapsulates the logic needed to draw the single-tiled Gecko texture
  */
 public class WidgetTileLayer extends Layer {
+    private static final String LOGTAG = "WidgetTileLayer";
 
     private int[] mTextureIDs;
     private CairoImage mImage;
@@ -110,7 +111,16 @@ public class WidgetTileLayer extends Layer {
                                 0);
 
         float top = viewport.height() - (bounds.top + bounds.height());
+
+        // There may be errors from a previous GL call, so clear them first because
+        // we want to check for one below
+        while (GLES11.glGetError() != GLES11.GL_NO_ERROR);
+
         GLES11Ext.glDrawTexfOES(bounds.left, top, 0.0f, bounds.width(), bounds.height());
+        int error = GLES11.glGetError();
+        if (error != GLES11.GL_NO_ERROR) {
+            Log.i(LOGTAG, "Failed to draw texture: " + error);
+        }
     }
 }
 

widget/android/AndroidGraphicBuffer.cpp

@@ -234,6 +234,11 @@ private:
 
 namespace mozilla {
 
+static void clearGLError()
+{
+  while (glGetError() != GL_NO_ERROR);
+}
+
 static bool ensureNoGLError(const char* name)
 {
   bool result = true;
@@ -443,6 +448,7 @@ AndroidGraphicBuffer::Bind()
     return false;
   }
 
+  clearGLError();
   sGLFunctions.fImageTargetTexture2DOES(GL_TEXTURE_2D, mEGLImage);
   return ensureNoGLError("glEGLImageTargetTexture2DOES");
 }