Initialize our quads to zero before we gl_->BufferData() with them.

cc/output/geometry_binding.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_OUTPUT_GEOMETRY_BINDING_H_
 #define CC_OUTPUT_GEOMETRY_BINDING_H_
 
 #include "base/basictypes.h"
 #include "cc/output/gl_renderer.h"  // For the GLC() macro.
 #include "gpu/command_buffer/client/gles2_interface.h"
@@ skipping 11 matching lines @@
 namespace cc {
 
 struct GeometryBindingVertex {
   float a_position[3];
   float a_texCoord[2];
   // Index of the vertex, divide by 4 to have the matrix for this quad.
   float a_index;
 };
 
 struct GeometryBindingQuad {
+  GeometryBindingQuad();
+  GeometryBindingQuad(const GeometryBindingVertex& vert0,
+                      const GeometryBindingVertex& vert1,
+                      const GeometryBindingVertex& vert2,
+                      const GeometryBindingVertex& vert3);
   GeometryBindingVertex v0, v1, v2, v3;
 };
 
 struct GeometryBindingQuadIndex {
+  GeometryBindingQuadIndex();
+  GeometryBindingQuadIndex(uint16 index0,
+                           uint16 index1,
+                           uint16 index2,
+                           uint16 index3,
+                           uint16 index4,
+                           uint16 index5);
+
   uint16 data[6];
 };
 
 class DrawQuad;
 class DrawPolygon;
 
 struct GeometryBinding {
   // All layer shaders share the same attribute locations for the vertex
   // positions and texture coordinates. This allows switching shaders without
   // rebinding attribute arrays.
   static int PositionAttribLocation() { return 0; }
   static int TexCoordAttribLocation() { return 1; }
   static int TriangleIndexAttribLocation() { return 2; }
 };
 
 void SetupGLContext(gpu::gles2::GLES2Interface* gl,
                     GLuint quad_elements_vbo,
                     GLuint quad_vertices_vbo);
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_GEOMETRY_BINDING_H_