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

cc/output/dynamic_geometry_binding.cc

 // Copyright 2015 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.
 
 #include "cc/output/dynamic_geometry_binding.h"
 
 #include "cc/output/gl_renderer.h"  // For the GLC() macro.
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "ui/gfx/geometry/rect_f.h"
 
 namespace cc {
 
 DynamicGeometryBinding::DynamicGeometryBinding(gpu::gles2::GLES2Interface* gl)
     : gl_(gl), quad_vertices_vbo_(0), quad_elements_vbo_(0) {
-  GeometryBindingQuad quads[8];
-  GeometryBindingQuadIndex quad_indices[8];
+  GeometryBindingQuad quads[1];
+  GeometryBindingQuadIndex quad_indices[1];
 
   static_assert(sizeof(GeometryBindingQuad) == 24 * sizeof(float),
                 "struct Quad should be densely packed");
   static_assert(sizeof(GeometryBindingQuadIndex) == 6 * sizeof(uint16_t),
                 "struct QuadIndex should be densely packed");
 
   GLC(gl_, gl_->GenBuffers(1, &quad_vertices_vbo_));
   GLC(gl_, gl_->GenBuffers(1, &quad_elements_vbo_));
 
   GLC(gl_, gl_->BindBuffer(GL_ARRAY_BUFFER, quad_vertices_vbo_));
@@ skipping 16 matching lines @@
   GeometryBindingVertex v0 = {
       {quad.p1().x(), quad.p1().y(), 0.0f}, {uv[0], uv[1]}, 0.0f};
   GeometryBindingVertex v1 = {
       {quad.p2().x(), quad.p2().y(), 0.0f}, {uv[2], uv[3]}, 1.0f};
   GeometryBindingVertex v2 = {
       {quad.p3().x(), quad.p3().y(), 0.0f}, {uv[4], uv[5]}, 2.0f};
   GeometryBindingVertex v3 = {
       {quad.p4().x(), quad.p4().y(), 0.0f}, {uv[6], uv[7]}, 3.0f};
 
   GeometryBindingQuad local_quad = {v0, v1, v2, v3};
-  GeometryBindingQuadIndex quad_index = {{static_cast<uint16>(0),
-                                          static_cast<uint16>(1),
-                                          static_cast<uint16>(2),
-                                          static_cast<uint16>(3),
-                                          static_cast<uint16>(0),
-                                          static_cast<uint16>(2)}};
+  GeometryBindingQuadIndex quad_index = {static_cast<uint16>(0),
+                                         static_cast<uint16>(1),
+                                         static_cast<uint16>(2),
+                                         static_cast<uint16>(3),
+                                         static_cast<uint16>(0),
+                                         static_cast<uint16>(2)};
 
   GLC(gl_, gl_->BufferSubData(GL_ARRAY_BUFFER, 0, sizeof(GeometryBindingQuad),
                               &local_quad));
   GLC(gl_, gl_->BufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0,
                               sizeof(GeometryBindingQuadIndex), &quad_index));
 }
 
 void DynamicGeometryBinding::PrepareForDraw() {
   SetupGLContext(gl_, quad_elements_vbo_, quad_vertices_vbo_);
 }
 
 }  // namespace cc